Alvarez-Martin C, Ribera A, Marsal JR, Ariza-Sole A, Perez-Hoyos S, Oristrell G, Soriano-Colome T, Romaguera R, Pijoan JI, Lidon RM, Mauri J, Ferreira-Gonzalez I. Dynamics of emergency cardiovascular hospital admissions and in-hospital mortality during the COVID-19 pandemic: time series analysis and impact of socioeconomic factors. Front. Cardiovasc. Med. 2022 Apr 26. doi: 10.3389/fcvm.2022.827212
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