@article{GDZPPN00218186X,
title = {On the representation of rational numbers as a sum of a fixed number of unit fractions.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {222},
year = {1966},
pages = {207-213},
zbl = {0141.04403},
url = {http://dml.mathdoc.fr/item/GDZPPN00218186X}
}
Rav, Yehuda. On the representation of rational numbers as a sum of a fixed number of unit fractions.. Journal für die reine und angewandte Mathematik, Tome 222 (1966) pp. 207-213. http://gdmltest.u-ga.fr/item/GDZPPN00218186X/