Kečkić, J. D. (1970). A differential operator and its applications to partial differential equations and nonanalytic functions. Univerzitet, Elektrotehnički fakultet].
Dyfyniad Arddull ChicagoKečkić, Jovan D. A Differential Operator and Its Applications to Partial Differential Equations and Nonanalytic Functions. [Beograd: Univerzitet, Elektrotehnički fakultet], 1970.
Dyfyniad MLAKečkić, Jovan D. A Differential Operator and Its Applications to Partial Differential Equations and Nonanalytic Functions. Univerzitet, Elektrotehnički fakultet], 1970.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.