The widely accepted linguistics term "Japonic languages" was coined by Serafim to identify and characterise the Japanese which is spoken on the main islands of Japan and the Ryukyuan spoken on the island of Okinawa and the Ryukyu Islands.
At the end of Serafim's studies at the University of California, Berkeley in 1968, he was awarded a B.A. in Oriental Languages. After further study at the University of Hawaii, he earned a master's degree in East Asian Languages in 1976. His Ph.D. in Linguistics was conferred by Yale University in 1984.
- Shodon: the Prehistory of a Northern Ryukyuan Dialect of Japanese (1984)
- Early Japanese Vocalism and Vowel Concord (1976)
- Library of Congress Authority file, Serafim, Leon Angelo n87-834425
- Shimabukuro, Moriyo. (2007). The Accentual History of the Japanese and Ryukyuan Languages: a Reconstruction, p. 1.
- University of Hawai'i at Mānoa, Leon Serafim Archived 2011-04-23 at the Wayback Machine
- Center for Japanese Studies.
- University of Hawaii Foundation press release, "First Okinawan Studies Endowment Fund," April 9, 2010; Center for Okiniawan Studies
- WorldCat Identities Archived 2010-12-30 at the Wayback Machine: Serafim, Leon Angelo
- Shimabukuro, Moriyo. (2007). The Accentual History of the Japanese and Ryukyuan Languages: a Reconstruction. London: Global Oriental. ISBN 9781901903638; OCLC 149189163