@book { Lossistemastemporalesdelespaolydelalemn,
    title = "Los sistemas temporales del español y del alemán",
    author = "Raúl {Sánchez Prieto}",
    year = "2011",
    publisher = "Meidenbauer",
    address = ", Germany",
    url = "https://www.peterlang.com/document/1136388"
}