Dyfyniad APA

FRBSF Economic Letter. Federal Reserve Bank of San Francisco.

Dyfyniad Arddull Chicago

FRBSF Economic Letter. Federal Reserve Bank of San Francisco.

Dyfyniad MLA

FRBSF Economic Letter. Federal Reserve Bank of San Francisco.

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