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2. American National Standard Institute (1989 ) ANSI Z87.1-1989. Practice for Occupational and Educational Eye and Face Protection. New York. N.Y., U.S.A.
3. Canadian Standards Association (1992 ) CAN/CSA-Z94. 3 -92 . Industrial Eye and Face Protectors . Rexdale, Ontario, Canada, pp. 3 -92 .