Dyfyniad APA
Unger, I., & Unger, D. (1995). These United States: The questions of our past (6th, combined ed.). Prentice Hall.
Dyfyniad Arddull Chicago
Unger, Irwin, and Debi Unger. These United States: The Questions of Our Past. 6th, combined ed. Englewood Cliffs, N.J.: Prentice Hall, 1995.
Dyfyniad MLA
Unger, Irwin, and Debi Unger. These United States: The Questions of Our Past. 6th, combined ed. Prentice Hall, 1995.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.