1. ACGIH (1990) “Threshold limit values for chemical substances and physical agents in the work environment and biological exposure indices with intended changes for 1987-88”. American Conference of Governmental Industrial Hygienists, Cincinnati OH, USA.
2. ACGIH (1988) “Industrial ventilation - a manual of recommended practice”, American Conference of Governmental Industrial Hygienists, Cincinnati OH, USA.
3. Alevantis, L.E. and Hayward, S.B. (1987) “A computer-controlled system for measuring building air exchange rates using sulphur hexafluoride as a tracer gas”. In: Proceedings of Indoor Air 1987, 3, 165-169.