@article{AM2_1983__26_136983,
     author = {Harshinder Singh},
     title = {On some regularity properties of quadratic stochastic processes.},
     journal = {Aequationes mathematicae},
     pages = {59--63},
     publisher = {mathdoc},
     volume = {26},
     year = {1983},
     zbl = {0533.60075},
     url = {http://geodesic.mathdoc.fr/item/AM2_1983__26_136983/}
}