@book { ALearnersGuidetotheOldChurchSlavicLanguageTeil1GrammarwithExercises,
    title = "A Learner's Guide to the Old Church Slavic Language. Teil 1: Grammar with Exercises",
    author = "Philip J. {Regier}",
    year = "1977",
    publisher = "Biblion",
    address = ", Germany",
    doi = "10.3726/b12392",
    url = "https://www.peterlang.com/document/1066876"
}