diff --git a/.DS_Store b/.DS_Store
index 8618e22..ff21beb 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/build.gradle b/build.gradle
index 18204b9..fe99304 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,5 +1,5 @@
 group 'org.openkoreantext'
-version '6.0.0.2'
+version '6.1.1.2'
 
 apply plugin: 'java'
 apply plugin: 'maven'
@@ -20,7 +20,7 @@ configurations {
 }
 
 ext {
-    elasticsearchVersion = '6.0.0'
+    elasticsearchVersion = '6.1.1'
     openKoreanTextVersion = '2.1.0'
 }
 
@@ -64,6 +64,12 @@ task javadocJar(type: Jar) {
     from javadoc
 }
 
+tasks.withType(Javadoc) {
+    options.addStringOption('Xdoclint:none', '-quiet')
+    options.addStringOption('encoding', 'UTF-8')
+    options.addStringOption('charSet', 'UTF-8')
+}
+
 task sourcesJar(type: Jar) {
     classifier = 'sources'
     from sourceSets.main.allSource
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 8b4dbf1..88cc6a6 100644
--- a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextPhraseExtractor.java
+++ b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextPhraseExtractor.java
@@ -13,8 +13,6 @@
 
 /**
  * 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 {
 
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 09a22e1..e516768 100644
--- a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextStemmer.java
+++ b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextStemmer.java
@@ -11,8 +11,6 @@
 
 /**
  * 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 {
 
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 79a9c37..ba9e2ef 100644
--- a/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextTokenizer.java
+++ b/src/main/java/org/apache/lucene/analysis/ko/OpenKoreanTextTokenizer.java
@@ -17,8 +17,6 @@
 
 /**
  * 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 {