@article{
    ovaska03,
    author = {Ovaska, Seppo and Vainio, Olli and P\"{o}ll\"{a}, Matti},
    title = "Adaptive filtering using multiplicative general parameters for zero-crossing detection",
    journal = "IEEE Transactions on Industrial Electronics",
    number = "6",
    month = "December",
    volume = "50",
    year = "2003",
    pages = "1340--1342"
}