David Ladd

Justice; Part I of the Metaphysics of Morals. 1st ed. Translated by John Ladd. Indianapolis: Bobbs-Merrill, 1965. [introduction and most of part I] Kant

"Untitled Document". abacus.bates.edu. נבדק ב-2016-01-16. Nevin, David (1970). Muskie of Maine. Ladd Library, Bates College: Random House, New York. p. 99. .

Martin Lipset And David Riesman. New York: Mcgraw-Hill Book Co., 1975 Professors, unions, and American higher education/ Everett Carll Ladd, Jr., and Seymour

Psychological Bulletin 119, 1996-01, עמ' 51–69 doi: 10.1037/0033-2909.119.1.51 Ladd Wheeler, Motivation as a determinant of upward comparison, Journal of Experimental

Forrister". Forristertn.tumblr.com. נבדק ב-30 בדצמבר 2015. {{cite web}}: (עזרה) Ladd, Olivia (23 בפברואר 2015). "From Memphis to Murfreesboro: Musician Julien