Dyfyniad APA

FIELD, B. C., & FIELD, B. C. (1994). Environmental Economics An Introduction Barry C. Field. McGraw-Hill.

Dyfyniad Arddull Chicago

FIELD, Barry C., and Barry C. FIELD. Environmental Economics An Introduction Barry C. Field. McGraw-Hill, 1994.

Dyfyniad MLA

FIELD, Barry C., and Barry C. FIELD. Environmental Economics An Introduction Barry C. Field. McGraw-Hill, 1994.

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