Dyfyniad APA

Gale Research Company. (1987). Research Centers directory. Gale.

Dyfyniad Arddull Chicago

Gale Research Company. Research Centers Directory. Detroit, Mich.: Gale, 1987.

Dyfyniad MLA

Gale Research Company. Research Centers Directory. Gale, 1987.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.