1. ASTM., 1971 . Maintaining constant relative humidity by means of aqueous solutions, E104-51 , pp. 46 -49 , ASTM Annual Book of Standards, American Society for Testing Materials, Philadelphia, PA.
2. ASTM, 1988 . Standard test methods for tensile properties of thin plastic sheeting, D882-88 , pp. 324 -332 , ASTM Annual Book of Standards, American Society for Testing Materials, Philadelphia, PA.