@misc{Axelson_Olav_Negative,
 author={Axelson, Olav},
 copyright={Axelson, Olav},
 howpublished={online},
 publisher={Nofer Institute of Occupational Medicine},
 publisher={Polish Association of Occupational Medicine},
 language={eng},
 type={serial - article},
 type={language document},
 title={Negative and non-positive epidemiological studies},
}