Myrzanov Zh. E.
Ukr. Mat. Zh. - 1993. - 45, № 4. - pp. 579–581
A cubic formula containing partial integrals is considered on a class of functions of two variables. It is shown that the integral of a mixed Hermite spline gives the best cubic formula for the given class. The coincidence of cubic formulas, which are exact for odd and even mixed Hermite splines, is established.
Ukr. Mat. Zh. - 1987. - 39, № 5. - pp. 598–602
Ukr. Mat. Zh. - 1986. - 38, № 4. - pp. 509–514