1. L.E. Dickson, History of the Theory of Numbers, Vol. II, Carnegie Institute, Washington, 1920. Reprint: Chelsea, New York, 1971.
2. P. Erdős, A theorem of Sylvester and Schur, J. London Math. Soc. 9 (1934), 282–288.
3. P. Erdős, On sequences of integers no one of which divides the product of two others and on some related problems, Mitt. Forsch. Inst. Math. Mech. Univ. Tomsk 2 (1938), 74–82.
4. P. Erdős, Note on products of consecutive integers, J. London Math. Soc. 14 (1939), 194–198.
5. P. Erdős, Note on the product of consecutive integers (II), J. London Math. Soc. 14 (1939), 245–249.