Library of Congress. Copyright Office. (1985). Copyright basics. Copyright Office, Library of Congress.
Dyfyniad Arddull ChicagoLibrary of Congress. Copyright Office. Copyright Basics. Washington, D.C.: Copyright Office, Library of Congress, 1985.
Dyfyniad MLALibrary of Congress. Copyright Office. Copyright Basics. Copyright Office, Library of Congress, 1985.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.