@misc{nonlinear+second+order+delay+differential+equation,
    author = {Byszewski, Ludwik},
    title = {Nonlinear second-order delay differential equation},
    journal = {Technical Transactions},
    address = {Kraków},
    publisher = {<a href=\"http://www.wydawnictwo.pk.edu.pl/\" target=\"_blank\">Wydawnictwo PK</a>},
    date = {2019},
    number = {Vol. 116, iss. 3},
    ISSN = {0011-4561}
}