From left: <a href="https://en.wikipedia.org/wiki/Mao_Zedong" class="extiw" title="w:Mao Zedong">Mao Zedong</a>, <a href="https://en.wikipedia.org/wiki/Peng_Zhen" class="extiw" title="w:Peng Zhen">Peng Zhen</a>, <a href="https://en.wikipedia.org/wiki/Norodom_Sihanouk" class="extiw" title="w:Norodom Sihanouk">Norodom Sihanouk</a> and <a href="https://en.wikipedia.org/wiki/Liu_Shaoqi" class="extiw" title="w:Liu Shaoqi">Liu Shaoqi</a><br>Text caption: Judging that relations with China were important to Cambodia's fragile neutrality. Prince Norodom Sihanouk (in the dark tunic) went to Peking in 1965 for discussions with Chairman Mao Tse-tung (left). (Center of Military History)
Washington DC: Center of Military History
Joel D. Meyerson, <i>United States Army in Vietnam: Images of a Lengthy War</i>, 1986, Center of Military History, ISBN 10: 0160016207, p. 197