def bib_to_string(bibliography):
    """ dict of dict -> str
    Take a biblatex bibliography represented as a dictionary
    and return a string representing it as a biblatex file.
    """
    string = ''
    for entry in bibliography:
        string += '\n@{}{{{},\n'.format(
            bibliography[entry]['type'],
            bibliography[entry]['id']
        )
        for field in bibliography[entry]:
            if field != 'id' and field != 'type':
                string += '\t{} = {{{}}},\n'.format(
                    field,
                    bibliography[entry][field]
                )
        string = string[:-2] + '}\n'
    return string