@Book{OL4548376M,
    title: {The Marx-Engels reader},
    author: {Karl Marx and Tucker, Robert C.},
    publisher: {Norton},
    year: {1978},
    place: {New York},
}

@Author{OL48230A,
    name: {Karl Marx},
    birth_date: {5 May 1818}
    , death_date: {14 March 1883}
}
@Author{OL446393A,
    name: {Tucker, Robert C.},
}