FitzGerald, Robert David, 1902-
Robert D. FitzGerald
University of Queensland Press, 1987
 Buku Teks SO
Day, A. Grove (Arthur Grove), 1904-1994
Robert D. FitzGerald
Twayne, 1974
 Buku Teks SO
Robert, D.S.
Islam concise introduction / D. S . Robert
Harper & Row, 1981
 Buku Teks SO
Intonational phonology / D. Robert Ladd
Cambridge University Press, 2008
 eBooks
Crumbley, D Larry
Dictionary of tax terms / D. Larry Crumbley, Jack P. Friedman and Susan B. Anders
Barron's Educational Series, 1994
 Buku Teks SO