@book { ExpertensucheinOnlineCommunities,
    title = "Expertensuche in Online Communities",
    author = "Jochen {Schwarz}",
    year = "2000",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832428877",
    url = "https://m.diplom.de/document/218614"
}