Bond JC, Geller RJ, White KO, Hatch EE, Rothman KJ, Wise LA. Concordance of self-reported sexual intercourse frequency between members of mixed-sex couples attempting conception. Can J Hum Sex. 2022 Dec;31(3):342-53. doi: 10.3138/cjhs.2021-0059
Yopp JM, Park EM, Edwards T, Deal A, Rosenstein DL. Overlooked and underserved: widowed fathers with dependent-age children. Palliat Support Care. 2015 Oct;13(5):1325-34. doi: 10.1017/S1478951514001321