Calligraphy by Chairman Lin Piao in 1961. China Pictorial 8.266 (1970): 2.
Original caption: "Strive to train more 'four-good' companies. This brilliant
inscription, resplendent with Chairman Mao's thinking on army building, was written by Vice-Chairman Lin Piao in 1961 for a PLA unit stationed in Kwangchow
area."