1. Maynard, A. D., Warheit, D. & Philbert, M. A. Toxicol. Sci. 120, S109–S129 (2011).
2. Holdren, J. P., Sunstein, C. R. & Siddiqui, I. A. Policy Principles for the U.S. Decision-making Concerning Regulation and Oversight of Applications of Nanotechnology and Nanomaterials (Executive Office of the President, 2011).