@book { GuaranaquJoparaall,
    title = "Guaraní aquí. Jopara allá",
    author = "Hedy {Penner}",
    year = "2014",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    doi = "10.3726/978-3-0351-0764-7",
    url = "https://www.peterlang.com/document/1053175"
}