@misc{flow+forces+acting+on+the+spool+of+directional+control+valve,
    author = {Rajda, Janusz i Lisowski, Edward},
    title = {Flow forces acting on the spool of directional control valve},
    journal = {Technical Transactions, iss. 5. Mechanics, iss. 1-M, s. 349-356},
    address = {Kraków},
    publisher = {<a href=\"http://www.wydawnictwo.pk.edu.pl/\" target=\"_blank\">Wydawnictwo PK</a>},
    date = {2013}
}