@book { MarxUntersuchungzurLagedesProletariats,
    title = "Marx' Untersuchung zur Lage des Proletariats",
    author = "Manuel {Irman}",
    year = "2011",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783656033424",
    url = "https://www.hausarbeiten.de/document/180510"
}