Vinceti M, Balboni E, Rothman KJ, Teggi S, Bellino S, Pezzotti P, Ferrari F, Orsini N, Filippini T. Substantial impact of mobility restrictions on reducing COVID-19 incidence in Italy in 2020. J Travel Med. 2022 Sep;29(6):taac081. doi: 10.1093/jtm/taac081
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
Knox D, Gibson L, Zusman ME, Gallmeier C. Why college students end relationships. Coll Stud J. 1997 Jan 1;31(4):449-52.