Cook, F. S., Morrison, P. C., Trytten, J. M., & Whale, L. J. (1959). Gregg Junior high typing. McGraw-Hill book Co. Inc..
Dyfyniad Arddull ChicagoCook, Fred S., Phyllis C. Morrison, John M. Trytten, and Leslie J. Whale. Gregg Junior High Typing. London: McGraw-Hill book Co. Inc., 1959.
Dyfyniad MLACook, Fred S., et al. Gregg Junior High Typing. McGraw-Hill book Co. Inc., 1959.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.