@book { DieAusdifferenzierungdessozialenSystemsSport, title = "Die Ausdifferenzierung des sozialen Systems Sport", author = "Stefan {Hasse}", year = "2011", publisher = "GRIN Verlag", address = "München, Germany", doi = "10.3239/9783640945863", url = "https://www.hausarbeiten.de/document/174227" }