@article{TRSPY_1987_180_a89,
     author = {N. E. Lushpai and I. L. Zaichenko},
     title = {Extremal numerical integration formulas for classes of differentiable periodic functions},
     journal = {Informatics and Automation},
     pages = {152--154},
     publisher = {mathdoc},
     volume = {180},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_1987_180_a89/}
}