Edwards PET, Parsons GR, Myers KH. The economic value of viewing migratory shorebirds on the Delaware Bay: an application of the single-site travel cost model using on-site data. Hum Dimens Wildl. 2011;16(6):435-44. doi: 10.1080/10871209.2011.608180
Clarkson TB, Anthony MS, Klein KP. Effects of estrogen treatment on arterial wall structure and function. Drugs. 1984;47(Suppl 2):42-51.