@Book{OL3196280M,
    title: {Marketing},
    author: {William M. Pride},
    publisher: {Houghton Mifflin},
    year: {1985},
    place: {Boston},
}

@Work{OL1807516W,
    title: {Marketing},
    author: {Philip Kotler and Gary Armstrong},
    first_publish_year: {1987}
}

@Author{OL216799A,
    name: {Philip Kotler},
    birth_date: {May 27, 1931}
}
@Author{OL1430543A,
    name: {Gary Armstrong},
    birth_date: {1943}
}