@misc{humic+substances+and+significance+of+their+application+a+review,
    author = {Kłeczek, Aneta i Anielak, Anna M.},
    title = {Humic substances and significance of their application – a review},
    journal = {Technical Transactions},
    address = {Warsaw},
    publisher = {Sciendo},
    date = {2021},
    number = { Vol. 118, iss. 1}
}