1. NIOSH (content source); Draggan S (topic editor). National Institute for Occupational Safety and Health (NIOSH), United States. In: Cleveland CJ, editor. Encyclopedia of earth. Washington, DC, USA: Environmental Information Coalition, National Council for Science and the Environment; 2006. Retrieved December 20, 2010, from: http://www.eoearth.org/article/National_Institute_ for_Occupational_Safety_and_Health_ (NIOSH),_United_States
2. American National Standards Institute (ANSI). Safety signs and labels (Standard No. ANSI Z535.4-2007). New York, NY, USA: ANSI; 2007.
3. Lesch MF. A semantic relatedness paradigm for assessing comprehension of warning symbols. In: Proceedings of the 49th Annual Meeting of the Human Factors and Ergonomics Society. Santa Monica, CA, USA: Human Factors and Ergonomics Society; 2005. p. 782–5.
4. Goldsworthy RC, Mayhorn CB. On warning symbols, text and “getting it right”: the iterative refinement of a teratogenic pharmaceutical label. In: Proceedings of the 53th Annual Meeting of the Human Factors and Ergonomics Society. Santa Monica, CA, USA: Human Factors and Ergonomics Society; 2009. p. 1603–7.
5. American National Standards Institute (ANSI). Criteria for safety symbols (Standard No. ANSI Z535.3-2002). New York, NY, USA: ANSI; 2002.