References
- Ledbetter , J.O. 1972 . Air Pollution: Part A, Analysis , New York : Marcel Dekker .
- 1983 . Kitazawa Manufacture Manual for Aspirating Pump and Indicator Tubes , Japan : Kitazawa Co. .
- Manahan , S.E. 1984 . Environmental Chemistry, , 4th edition , Boston : Willard Grant Press .