pkuthss.bib: update bibliography.

doc/readme/pkuthss.bib

@@ -162,7 +162,7 @@
 
 @online{lwolf,
 	author = {lwolf},
-	title = {学士(硕/博)毕业论文模板 [基于 dypang 的模板]},
+	title = {学士（硕/博）毕业论文模板 [基于 dypang 的模板]},
 	type = {EB/OL},
 	date = {2007-05-15},
 	url = {http://bdwm.net/a.php?b/MathTools/M.1179239165.A/5A2D5A2.rar},
@@ -190,37 +190,23 @@
 	language = {chinese},
 }
 
-@online{pku-copyright,
-	author = {北京大学研究生院},
-	title = {北京大学学位论文版权声明(首页)},
-	type = {M/OL},
-	year = {2014},
-	url = {http://grs.pku.edu.cn/document/20140416145103446514.doc},
-	urldate = {2014-05-24},
-	language = {chinese},
-}
-
 @online{pku-originauth,
 	author = {北京大学研究生院},
-	title = {北京大学学位论文原创性声明和使用授权说明},
+	title = {北京大学学位论文原创性声明和使用授权说明（末页限重新申请学位使用）},
 	type = {M/OL},
-	year = {2014},
-	url = {http://grs.pku.edu.cn/document/20140416145000135438.doc},
-	urldate = {2014-05-24},
+	date = {2014-04-16},
+	url = {http://grs.pku.edu.cn/document/20140416144734027222.doc},
+	urldate = {2015-04-26},
 	language = {chinese},
 }
 
-@incollection{pku-thesisstyle,
-	author = {北京大学研究生院},
-	title = {北京大学研究生学位论文的基本要求与书写格式（2007 年 6 月修订）},
+@online{pku-thesisstyle,
+	author = {北京大学学位办公室},
+	title = {北京大学研究生学位论文写作指南},
 	type = {M/OL},
-	bookauthor = {北京大学研究生院},
-	booktitle = {北京大学研究生手册},
-	publisher = {北京大学},
-	year = {2013},
-	pages = {30-35},
-	url = {http://grs.pku.edu.cn/document/20131031200524521428.pdf},
-	urldate = {2014-05-24},
+	date = {2014-05},
+	url = {http://grs.pku.edu.cn/document/20140918140526208797.pdf},
+	urldate = {2015-04-26},
 	language = {chinese},
 }