1. Abbott Laboratories. Synthroid® Product Insert/Physician Information. http://www.accessdata.fda.gov/drugsatfda_docs/label/2008/021402s017lbl.pdf (accessed 11 October 2010). North Chicago, 2008.
2. Anonymous reviewer comments, received December 2010.
3. D. M. Bressoud. “Personal Thoughts on Mature Teaching." InHow to Teach Mathematicsby S.G. Krantz. 2nd ed., 173–181. American Mathematical Society, Providence, 1999.
4. Duramed Pharm., Inc. Aygestin® Product Insert/Physician Information. http://www.accessdata.fda.gov/drugsatfda_docs/label/2007/018405s023lbl.pdf (accessed 11 October 2010). Pomona, 2007.
5. G. A. Koch. Pharmacokinetics. A module of the Biological ESTEEM Collection, published by the BioQUEST Curriculum Consortium. http://bioquest.org/esteem/esteem_details.php?product_id=39111 (accessed 23 September 2011). 2011.