Dyfyniad APA

(1989). Engineering geology field manual. U S Department of interior.

Dyfyniad Arddull Chicago

Engineering Geology Field Manual. U S: U S Department of interior, 1989.

Dyfyniad MLA

Engineering Geology Field Manual. U S Department of interior, 1989.

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