1. MSHA (2018) 30 CFR 57.5002 - Exposure Monitoring - Safety and Health Standards - Underground Metal and Nonmetal Mines.
https://www.ecfr.gov/cgi-bin/text-idx?SID=0bcad0e6ebc19aadf8510f191ea706e9&mc=true&node=se30.1.57_15002&rgn=div8
2. Cash DA (1999) Introduction to operator air sampling. Mine Safety and Health Administration, Arlington
3. MSHA (2018) Metal/nonmetal operator monitoring requirements guidance.
https://arlweb.msha.gov/S&HINFO/ExposureGuidance/ExposureGuidance.asp
4. OSHA permissible exposure limits, OSHA annotated table Z-1.
https://www.osha.gov/dsg/annotated-pels/tablez-1.html
. Accessed 13 Oct 2017
5. Agasty A, Clausen E, Kellner M, Langefeld O (2013) After blast re-entry time for a room and pillar operation. Paper presented at the the Australian Mine Ventilation Conference, Adelaide, SA