Dyfyniad APA

(1991). In space (How things work). Alexandria, Virginia: Time-Life Books.

Dyfyniad Arddull Chicago

In Space (How Things Work). Alexandria, Virginia: Time-Life Books, 1991.

Dyfyniad MLA

In Space (How Things Work). Alexandria, Virginia: Time-Life Books, 1991.

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