Translation of: 'Vvedenie v teoriiu differentsial'nykh uravneniÄ s otkloniaiushchimsia argumentom'. 2nd ed. Moscow : Nauka Press, 1971.
Introduction to the theory and application of differential equations with deviating arguments by Lev Ernestovich El'sgol'ts. ISBN 0122377508. Published by Academic Press in 1973. Publication and catalogue information, links to buy online and reader comments.