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
Cain VS, Johannes CB, Avis NE, Mohr B, Schocken M, Skurnick J, Ory M. Sexual functioning and practices in a multi-ethnic study of midlife women: baseline results from SWAN. J Sex Res. 2003 Aug 1;40(3):266-76.