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
Norton EC, Zarkin GA, Calingaert B, Bradley CJ. The effect of maternal substance abuse on the cost of neonatal care. Inquiry. 1996;33(3):247-57.