Horwell, C., Williamson, B., Donaldson, K., Le Blond, J., Damby, D., & Bowen, L. (2012). The structure of volcanic cristobalite in relation to its toxicity; relevance for the variable crystalline silica hazard. Particle and Fibre Toxicology, 9, Article 44. https://doi.org/10.1186/1743-8977-9-44