12. European Standards EN 140 Respiratory Protective Devices: Half-masks, quarter-masks; requirements, testing, marking. European Committee for Standardization. (1998 г.)

13. Janssen Larry L., Bidwell Jeanne O., Efficiency of Degraded Electret Filters: Part II – Field Testing Against Workplace Aerosols Journal of the International Society for Respiratory Protection 2003г. Vol.20 p.81.

14. Janssen Larry, Bidwell Jeanne, Karen Cuta, and Thomas Nelson Workplace Performance of a Hood-Style Supplied-Air Respirator Journal of Occupational and Environmental Hygiene 2008г. Vol. 5 №7, p. 438–443.

15. Janssen Larry L., Nelson, Thomas J. and Cuta, Karen T. Workplace Protection Factors for an N95 Filtering Facepiece Respirator, Journal of Occupational and Environmental Hygiene 2007г. Vol 4 №9, p.698.

16. Hardis. K.E.; C.A. Cadena; G.J. Carlson; R.A. da ROZA. Correlation of Qualitative and Quantitative Results from Testing Respirator Fit American Industrial Hygiene Association Journal, 1983г. Vol. 44 №2, p. 78-87.

17. LENHART S. W. and D. L. CAMPBELL ASSIGNED PROTECTION FACTORS FOR TWO RESPIRATOR TYPES BASED UPON WORKPLACE PERFORMANCE TESTING Annals of Occupational Hygiene, 1984г. Vol. 28 № 2 p. 173-182.

18. Spear Terry M.; James DuMond; Carrie Lloyd; James H.Vincent An Effective Protection Factor Study of Respirators Used by Primary Lead Smelter Workers Applied Occupational and Environmental Hygiene 2000г. Vol.15 p.235.

19. Wu Ming-Tsang Assessment of the Effectiveness of Respirator Usage in Coke Oven Workers, American Industrial Hygiene Association Journal, 2002г. Vol. 63 №1, p. 72–75.

20. Zhuang Ziqing; Christopher C. Coffey; Paul A. Jensen; Donald L. Campbell; Robert B. Lawrence; Warren R. Myers Correlation Between Quantitative Fit Factors and Workplace Protection Factors Measured in Actual Workplace Environments at a Steel Foundry American Industrial Hygiene Association Journal, 2004г. Vol.64 №6 p.730.

21. 29 CFR 1910.134 Appendix A – Fit Testing Procedures (США, 1999, 2003г., www.osha.gov).