Kečkić, J. D. (1970). A differential operator and its applications to partial differential equations and nonanalytic functions. Univerzitet, Elektrotehnički fakultet].
Chicago-viite (17. p.)Kečkić, Jovan D. A Differential Operator and Its Applications to Partial Differential Equations and Nonanalytic Functions. [Beograd: Univerzitet, Elektrotehnički fakultet], 1970.
MLA-viite (8. p.)Kečkić, Jovan D. A Differential Operator and Its Applications to Partial Differential Equations and Nonanalytic Functions. Univerzitet, Elektrotehnički fakultet], 1970.
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