@Book{OL689394M,
    title: {The expression of the emotions in man and animals},
    author: {Charles Darwin},
    publisher: {Oxford University Press},
    year: {1997},
    place: {Oxford},
}

@Author{OL35839A,
    name: {Charles Darwin},
    birth_date: {12 February 1809}
    , death_date: {19 April 1882}
}