"[1] Focusing on the period from the 9th to the 15th centuries, he was the author of 19 volumes of history in English and Chinese, a major contributor to two other large collaborative works, and over a hundred essays and reviews in history journals.
(1963) there before completing doctoral studies at Princeton with Frederick Mote and James T.C.
In 1968, he left for Columbia University where he began working on the Dictionary of Ming Biography.
His 1983 Morrison Lecture focused on the control of publishing in Chinese history.
[3] His most enduring work is on Song, Yuan and Ming politics and thought, including work in Journal of the American Oriental Society, Harvard Journal of Asiatic Studies, Journal of Asian History, Asia Major and a contribution to The Cambridge History of China on the period 1399–1435.