1. "The Air Pollution Consultant; Guidanceon HAP Early Reduction Compliance Extensions", (author unknown), Vol.1, Issue 2, pp2.1-2.13, Nov/Dec 1991.
2. Relative Contribution of Outdoor and Indoor Particle Sources to Indoor Concentrations
3. ACGIH (American Conference of Governmental and Industrial Hygienists), "Air Sampling Instruments", 4th ed., Cincinnati, OH, 1972.
4. ACGIH (American Conference of Governmental and Industrial Hygienists), "Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment with Intended Changes for 1977", PO Box 1937, Cincinnati, Ohio, 45201, 1977.