I recently read this book which consists of a collection of articles about Buddhist exchanges between Tibet and China from the Ming era up to the present.
This book would be of interest to anyone curious about Tibetan-Chinese-Mongol relations in that time period. The most interesting parts for me personally were about early 20th century exchanges between Tibetan and Chinese Buddhists. The book talks about Gangkar Rinpoche's activities giving many teachings to the Chinese, including several prominent warlords and GMD officials. Students of Chogyal Namkhai Norbu might be interested in a small footnote saying that he was registered under the name Loden Wangpo at the time he was working as a teacher together with Gangkar Rinpoche.
Other interesting parts include the early 20th translation of Tibetan texts to Chinese. Some of the lamas behind these translations include: Norlha Khutughtu Sonam Rapten, Drojechang Trashilhunpo Ngakchen Darpo Khutughtu, Dewe Jungne Gyelten Rinpoche, Lozang Tendzin Jikme Wangchuk Pelzangpo, Geshe Nomunqan Lama Dorje Chopa, Gushri Konchok Dorje. Some of the Chinese (both monastic and lay) involved were: Nenghai, Fazun, Guankong, Chaoyi, Yanding, Mankong and the lamen Sun Jingfeng and Tang Xiangming Even by 1934, these translations incorporated Roman, English-based transliterations of the mantras because they recognised that the Tibetan spelling preserved the Sanskrit pronunciation better than Chinese characters. Most of them were Gelugpas, although Norlha Khutughtu was a Nyingmapa. I remember reading an online article about a Chinese man who had accomplished the rainbow body being a disciple of Norlha Khutughtu.
The above mainly concerns translations of esoteric texts both mantras and dharanis. On the philosophical front, there was a great deal of early exchange going on as well, mainly concerned with the translation of Yogacara and logical texts. Some of the prominent authors mentioned include Lu Cheng and Fazun. Lu Cheng is apparently quite a well known Buddhist scholar in East Asia and drew up a plan of works to be translated from Tibetan to Chinese and a few texts missing from the Tibetan canon to be translated from Chinese to Tibetan. Fazun was one of the few Chinese at the time who actually went to a Tibetan monastery. He translated the Abhisamayalamkara and Dharamadharmatavibhaga to Chinese as well as Tsongkhapa's Lam Rim Chen Mo but unfortunately many of his other translations were lost in the Cultural Revolution. Han Jingqing studied for some time in Tibet and set up a Buddhist centre in Beijing in the 90s mainly teaching Yogacara.