APA استشهاد

Letwin, S. R. (1965). The pursuit of certainty. at the university Press.

استشهاد بنمط شيكاغو

Letwin, Shirley Robin. The Pursuit of Certainty. Cambridge: at the university Press, 1965.

MLA استشهاد

Letwin, Shirley Robin. The Pursuit of Certainty. at the university Press, 1965.