@book { TheStoryofanOperetta,
    title = "The Story of an Operetta",
    subtitle = "Le dernier sorcier by Pauline Viardot and Ivan Turgenev, Vol. 1",
    author = "Nicholas G. {Žekulin}",
    year = "1989",
    publisher = "Biblion",
    address = ", Germany",
    doi = "10.3726/b12996",
    url = "https://www.peterlang.com/document/1067337"
}