@article{Selmer_1976, title={On the number of prime divisors of a binomial coefficient.}, volume={39}, url={https://www.mscand.dk/article/view/11662}, DOI={10.7146/math.scand.a-11662}, journal={MATHEMATICA SCANDINAVICA}, author={Selmer, Ernst S.}, year={1976}, month={Jun.}, pages={271–281} }