@book { LeistungshindernisseundHaftungsbefreiungimVertragsrecht,
    title = "Leistungshindernisse und Haftungsbefreiung im Vertragsrecht",
    author = "Ji {Zhang}",
    year = "2022",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b20034",
    url = "https://www.peterlang.com/document/1263474"
}