Contacts related to mental illness and substance abuse in primary health care: A cross-sectional study comparing patients' use of daytime versus out-of-hours primary care in Norway / Contacts related to mental illness and substance abuse in primary health care: A cross-sectional study comparing patients' use of daytime versus out-of-hours primary care in Norway - Johansen, Ingrid H; Morken, Tone; Hunskaar, Steinar (Scandinavian Journal of Primary Health Care, 2010)