@book { MarktmachtverlagerungdurchSuchmaschinenbetreiber, title = "Marktmachtverlagerung durch Suchmaschinenbetreiber", author = "Max {Erhard}", year = "2014", publisher = "Peter Lang Verlag", address = "Berlin, Germany", doi = "10.3726/978-3-653-04462-1", url = "https://www.peterlang.com/document/1048671" }