APA način citiranja

Erdal, M., Johannessen, A., Askildsen, J. E., Eagan, T., Gulsvik, A., & Grønseth, R. (2014). Productivity losses in chronic obstructive pulmonary disease: A population-based survey. BMJ Open Respir Res.

Čikaški stil citiranja

Erdal, Marta, Ane Johannessen, Jan Erik Askildsen, Tomas Eagan, Amund Gulsvik, i Rune Grønseth. "Productivity Losses in Chronic Obstructive Pulmonary Disease: A Population-based Survey." BMJ Open Respir Res 2014.

MLA način citiranja

Erdal, Marta, et al. "Productivity Losses in Chronic Obstructive Pulmonary Disease: A Population-based Survey." BMJ Open Respir Res 2014.