Gelles, R. J., & Levine, A. (1999). Sociology: An introduction (6 th ed.). Boston: McGraw-Hill College.
Dyfyniad Arddull ChicagoGelles, Richard J., và Ann Levine. Sociology: An Introduction. 6 th ed. Boston: McGraw-Hill College, 1999.
Dyfyniad MLAGelles, Richard J., và Ann Levine. Sociology: An Introduction. 6 th ed. Boston: McGraw-Hill College, 1999.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.