Dyfyniad APA

Ron Willingham. The inner game of sellling. Free press.

Dyfyniad Arddull Chicago

Ron Willingham. The Inner Game of Sellling. Free press.

Dyfyniad MLA

Ron Willingham. The Inner Game of Sellling. Free press.

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