Smith, D. (1974). Simple navigation by the sun. Thomas reed.
Dyfyniad Arddull ChicagoSmith, David. Simple Navigation by the Sun. London: Thomas reed, 1974.
Dyfyniad MLASmith, David. Simple Navigation by the Sun. Thomas reed, 1974.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.