Dyfyniad APA

Library of Congress. (2009). Subject headings. Washington, DC: Library of Congress.

Dyfyniad Arddull Chicago

Library of Congress. Subject Headings. Washington, DC: Library of Congress, 2009.

Dyfyniad MLA

Library of Congress. Subject Headings. Washington, DC: Library of Congress, 2009.

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