@article{01209881,
title = {On periodic solutions of first order nonlinear differential equations with deviating arguments.},
journal = {Memoirs on Differential Equations and Mathematical Physics},
volume = {12},
year = {1997},
pages = {134-137},
zbl = {0927.34053},
language = {en},
url = {http://dml.mathdoc.fr/item/01209881}
}
Kiguradze, I. On periodic solutions of first order nonlinear differential equations with deviating arguments.. Memoirs on Differential Equations and Mathematical Physics, Tome 12 (1997) pp. 134-137. http://gdmltest.u-ga.fr/item/01209881/