Lefschetz, S. (1963). Differential equations: Geometric theory (2d ed.). New York: Interscience Publishers.
Dyfyniad Arddull ChicagoLefschetz, Solomon. Differential Equations: Geometric Theory. 2d ed. New York: Interscience Publishers, 1963.
Dyfyniad MLALefschetz, Solomon. Differential Equations: Geometric Theory. 2d ed. New York: Interscience Publishers, 1963.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.