Rohmah, S. N. “Correlation Study of Carbon Monoxide (CO) Air Exposure Level With Blood COHb Level of Basement Officer in Surabaya Mall”. JURNAL KESEHATAN LINGKUNGAN, vol. 11, no. 3, July 2019, pp. 225-33, doi:10.20473/jkl.v11i3.2019.225-233.