On 10 January, the work was re-issued to the delegates and sent to select units of the People's Liberation Army who received their advance copies for educating troops as well as for their comments. In May 1964, the PLA General Political Department, the chief political organ under Central Military Commission, revised "Quotations", adding a half title page with the slogan "Workers of the world, unite!" () in bold red letters, and endorsement leaves written by Lin Biao, Mao's chosen successor, that included three lines from the diary of revolutionary soldier Lei Feng who is considered a hero in China. This version was issued "for internal use" to the military leaders. Following discussions that expanded the book twice more—finally closing on 33 topics and 427 quotations by Mao—the commission began publishing the definitive version in May 1965.