Derrick, D. (1981). Navigation for Offshore and Ocean Sailors. David & Charles.
Dyfyniad Arddull ChicagoDerrick, David. Navigation for Offshore and Ocean Sailors. Newton Abbot: David & Charles, 1981.
Dyfyniad MLADerrick, David. Navigation for Offshore and Ocean Sailors. David & Charles, 1981.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.