@article{03996183,
title = {Functional differential equations - a reciprocity principle.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {9},
year = {1986},
pages = {807-810},
doi = {10.1155/S0161171286000996},
zbl = {0615.34063},
language = {en},
url = {http://dml.mathdoc.fr/item/03996183}
}
Williams, Lloyd K. Functional differential equations - a reciprocity principle.. International Journal of Mathematics and Mathematical Sciences, Tome 9 (1986) pp. 807-810. doi : 10.1155/S0161171286000996. http://gdmltest.u-ga.fr/item/03996183/