@misc{some+remarks+on+the+generalized+banach+contraction+principle,
    author = {Wesołowski, Krzysztof},
    title = {Some remarks on the generalized Banach contraction principle},
    journal = {Technical Transactions},
    address = {Kraków},
    publisher = {<a href=\"http://www.wydawnictwo.pk.edu.pl/\" target=\"_blank\">Wydawnictwo PK</a>},
    date = {2015},
    number = {Y. 112, iss. 1-NP}
}