@misc{ wiki:SallanKey,
    author = "{Wikipedia contributors}",
    title = "Sallen–Key topology --- {Wikipedia}{,} The Free Encyclopedia",
    year = "2019",
    howpublished = "\url{https://en.wikipedia.org/w/index.php?title=Sallen%E2%80%93Key_topology&oldid=924138246}",
    note = "[Online; accessed 24-November-2019]"
}