Ala-Mursula, L.;    Vahtera, J.;    Pentti, J.;    Kivimäki, M.;      (2004)    Effect of employee worktime control on health: a prospective cohort study.                   Occupational and Environmental Medicine , 61  (3)   pp. 254-261.    10.1136/oem.2002.005983 <https://doi.org/10.1136/oem.2002.005983>.       Green open access