diff --git a/src/main/java/org/apache/lucene/analysis/ko/KoreanTokenPrepareable.java b/src/main/java/org/apache/lucene/analysis/ko/KoreanTokenPrepareable.java
index d43ffd8..ac74049 100644
--- a/src/main/java/org/apache/lucene/analysis/ko/KoreanTokenPrepareable.java
+++ b/src/main/java/org/apache/lucene/analysis/ko/KoreanTokenPrepareable.java
@@ -7,7 +7,7 @@
 import static org.openkoreantext.processor.tokenizer.KoreanTokenizer.KoreanToken;
 
 /**
- * To prepare korean token sequence
+ * To prepare korean token sequence.
  */
 public interface KoreanTokenPrepareable {
     /**
diff --git a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextAnalyzer.java b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextAnalyzer.java
index 500d343..e7e8c37 100644
--- a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextAnalyzer.java
+++ b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextAnalyzer.java
@@ -8,6 +8,9 @@
 import java.util.Arrays;
 import java.util.List;
 
+/**
+ * A default korean analyzer.
+ */
 public class OpenKoreanTextAnalyzer extends StopwordAnalyzerBase {
 
     private final static CharArraySet STOP_WORD_SET;
diff --git a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextNormalizer.java b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextNormalizer.java
index 6f5d4cf..f897f8f 100644
--- a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextNormalizer.java
+++ b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextNormalizer.java
@@ -6,6 +6,12 @@
 import java.io.IOException;
 import java.io.Reader;
 
+/**
+ * A character filter for normalizing input text.
+ * For normalizing text, it delegates input to {@link OpenKoreanTextProcessor}.
+ *
+ * ex) 그랰ㅋㅋ -> 그래ㅋㅋ, 재밌닿ㅎㅎㅎ -> 재밌다ㅎㅎ
+ */
 public class OpenKoreanTextNormalizer extends BaseCharFilter {
     private static final int READER_BUFFER_SIZE = 2048;
 
diff --git a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextPhraseExtractor.java b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextPhraseExtractor.java
index 9e090ae..8b4dbf1 100644
--- a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextPhraseExtractor.java
+++ b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextPhraseExtractor.java
@@ -11,6 +11,11 @@
 import static org.openkoreantext.processor.phrase_extractor.KoreanPhraseExtractor.KoreanPhrase;
 import static org.openkoreantext.processor.tokenizer.KoreanTokenizer.KoreanToken;
 
+/**
+ * Phrase Extractor. For extracting phrase, it delegates token to {@link OpenKoreanTextProcessor}
+ *
+ * {@see https://github.com/open-korean-text/open-korean-text/blob/master/src/main/scala/org/openkoreantext/processor/phrase_extractor/KoreanPhraseExtractor.scala}
+ */
 public class OpenKoreanTextPhraseExtractor extends OpenKoreanTextTokenFilter {
 
     public OpenKoreanTextPhraseExtractor(TokenStream input) {
diff --git a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextStemmer.java b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextStemmer.java
index cec5b23..09a22e1 100644
--- a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextStemmer.java
+++ b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextStemmer.java
@@ -9,6 +9,11 @@
 
 import static org.openkoreantext.processor.tokenizer.KoreanTokenizer.KoreanToken;
 
+/**
+ * Stems Adjectives and Verbs tokens.
+ *
+ * {@see https://github.com/open-korean-text/open-korean-text/blob/master/src/main/scala/org/openkoreantext/processor/stemmer/KoreanStemmer.scala}
+ */
 public final class OpenKoreanTextStemmer extends OpenKoreanTextTokenFilter {
 
     public OpenKoreanTextStemmer(TokenStream input) {
diff --git a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextTokenFilter.java b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextTokenFilter.java
index 55c7892..28b6327 100644
--- a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextTokenFilter.java
+++ b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextTokenFilter.java
@@ -13,6 +13,9 @@
 
 import static org.openkoreantext.processor.tokenizer.KoreanTokenizer.KoreanToken;
 
+/**
+ * Abstract token filter for processing korean tokens.
+ */
 public abstract class OpenKoreanTextTokenFilter extends TokenFilter implements KoreanTokenPrepareable {
 
     private final CharTermAttribute charTermAttribute = addAttribute(CharTermAttribute.class);
diff --git a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextTokenizer.java b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextTokenizer.java
index 320d37e..79a9c37 100644
--- a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextTokenizer.java
+++ b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextTokenizer.java
@@ -15,6 +15,11 @@
 import java.util.List;
 import java.util.Set;
 
+/**
+ * Provides Korean tokenization.
+ *
+ * {@see https://github.com/open-korean-text/open-korean-text/blob/master/src/main/scala/org/openkoreantext/processor/tokenizer/KoreanTokenizer.scala}
+ */
 public class OpenKoreanTextTokenizer extends Tokenizer implements KoreanTokenPrepareable {
 
     private static final int READER_BUFFER_SIZE = 1024;
diff --git a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextAnalyzerProvider.java b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextAnalyzerProvider.java
index 4d3adb0..ef40fbf 100644
--- a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextAnalyzerProvider.java
+++ b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextAnalyzerProvider.java
@@ -6,6 +6,9 @@
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.index.IndexSettings;
 
+/**
+ * A analyzer provider for openkoreantext.
+ */
 public class OpenKoreanTextAnalyzerProvider extends AbstractIndexAnalyzerProvider<OpenKoreanTextAnalyzer> {
 
     private final OpenKoreanTextAnalyzer analyzer;
diff --git a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextNormalizerFactory.java b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextNormalizerFactory.java
index 5043c54..b3ecb5d 100644
--- a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextNormalizerFactory.java
+++ b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextNormalizerFactory.java
@@ -9,6 +9,9 @@
 
 import java.io.Reader;
 
+/**
+ * A ES character-filter factory for {@link OpenKoreanTextNormalizer}.
+ */
 public class OpenKoreanTextNormalizerFactory extends AbstractCharFilterFactory implements MultiTermAwareComponent {
 
     public OpenKoreanTextNormalizerFactory(IndexSettings indexSettings, Environment env, String name, Settings settings) {
diff --git a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextPhraseExtractorFactory.java b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextPhraseExtractorFactory.java
index e33da26..486696c 100644
--- a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextPhraseExtractorFactory.java
+++ b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextPhraseExtractorFactory.java
@@ -6,6 +6,9 @@
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.index.IndexSettings;
 
+/**
+ * A ES token filter factory for {@link OpenKoreanTextPhraseExtractor}.
+ */
 public class OpenKoreanTextPhraseExtractorFactory extends AbstractTokenFilterFactory {
 
     public OpenKoreanTextPhraseExtractorFactory(IndexSettings indexSettings, Environment env, String name, Settings settings) {
diff --git a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextRedundantFilterFactory.java b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextRedundantFilterFactory.java
index b18ab0b..3344ad4 100644
--- a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextRedundantFilterFactory.java
+++ b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextRedundantFilterFactory.java
@@ -6,6 +6,9 @@
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.index.IndexSettings;
 
+/**
+ * A ES token filter factory for {@link OpenKoreanTextRedundantFilter}.
+ */
 public class OpenKoreanTextRedundantFilterFactory extends AbstractTokenFilterFactory {
 
     public OpenKoreanTextRedundantFilterFactory(IndexSettings indexSettings, Environment env, String name, Settings settings) {
diff --git a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextStemmerFactory.java b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextStemmerFactory.java
index 71e643e..a419b6d 100644
--- a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextStemmerFactory.java
+++ b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextStemmerFactory.java
@@ -6,6 +6,9 @@
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.index.IndexSettings;
 
+/**
+ * A ES token filter factory for {@link OpenKoreanTextStemmer}.
+ */
 public class OpenKoreanTextStemmerFactory extends AbstractTokenFilterFactory {
 
     public OpenKoreanTextStemmerFactory(IndexSettings indexSettings, Environment env, String name, Settings settings) {
diff --git a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextTokenizerFactory.java b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextTokenizerFactory.java
index c868d6a..28747e9 100644
--- a/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextTokenizerFactory.java
+++ b/src/main/java/org/elasticsearch/index/analysis/OpenKoreanTextTokenizerFactory.java
@@ -7,6 +7,9 @@
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.index.IndexSettings;
 
+/**
+ * A ES tokenizer factory for {@link OpenKoreanTextTokenizer}.
+ */
 public class OpenKoreanTextTokenizerFactory extends AbstractTokenizerFactory {
 
     public OpenKoreanTextTokenizerFactory(IndexSettings indexSettings, Environment env, String name, Settings settings) {