Dyfyniad APA

U. S. Social Security Administration. Office of Research and Statistics. (1999). Social security programs throughout the world, 1999. Gov't. Print. Off.

Dyfyniad Arddull Chicago

U. S. Social Security Administration. Office of Research and Statistics. Social Security Programs Throughout the World, 1999. Washington: Gov't. Print. Off, 1999.

Dyfyniad MLA

U. S. Social Security Administration. Office of Research and Statistics. Social Security Programs Throughout the World, 1999. Gov't. Print. Off, 1999.

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