Chen, Frederick Shih-Chung. “The Deathbed Injunction Sutra.” In Buddhist Stone Sutras in China. Sichuan Province, Volume 2, edited by Tsai Suey-Ling and Sun Hua 孫華, 48-52. Wiesbaden: Harrassowitz Verlag/Hangzhou: China Academy of Art Press, 2014.
Chen summarises work on the sources of the 佛遺教經 T389 in the following article:
Hosaka Gyokusen 保坂玉泉. “Butsuyuikyo gyo no seiritsu ni tsuite 佛遺教經の成立に就いて.” Komazawa daigaku jissen sojo kenkyukai nenpo 駒沢大学実践宗乗研究会年報 7 (1939): 30-39.
According to Chen, Hosaka identifies sources of specific passages in T389 in Chinese Agama texts, and in the Mahaparinirvana-mahasutra. T0389; 佛垂般涅槃略說教誡經