His Functions of English, 1977.

ALCS database, 3 Oct. 2006 (Leo Jones, born 7 July 1943)

Information from 678 converted Dec. 15, 2014 (head of Dept. of Advanced Studies, Anglo-Continental School of English, Bournemouth)

Biblioteca del congreso (Estados Unidos), 04 septiembre 2018: catálogo electrónico https://goo.gl/aDkcKW