浦志强等人‘六四’研讨会后失联 丁子霖被禁回北京 (Pu Zhiqiang and others “incommunicado” after June Fourth Symposium, Ding Zilin forbidden to return to Beijing before June 4)
Voice of America, May 5, 2014
http://www.voachinese.com/content/june-4th-beijing-20140505/1907779.html