Dyfyniad APA

(2008). Specification for Welding Procedure and Performance Qualification. American: Ametican Welding Society.

Dyfyniad Arddull Chicago

Specification for Welding Procedure and Performance Qualification. American: Ametican Welding Society, 2008.

Dyfyniad MLA

Specification for Welding Procedure and Performance Qualification. American: Ametican Welding Society, 2008.

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