\bib{1983/canfield}
\yr 1983
\mr 85j:11012
\by E. Rodney Canfield
\by Paul Erd\H os
\by Carl Pomerance
\paper On a problem of Oppenheim concerning ``factorisatio numerorum''
\jour Journal of Number Theory
\issn 0022--314X
\vol 17
\pages 1--28
\endref