Card, K., Armstrong, H., Carter, A., Cui, Z., Wang, L., Zhu, J., … Roth, E. (2018). Assessing the longitudinal stability of latent classes of substance use among gay, bisexual, and other men who have sex with men. Drug and Alcohol Dependence, 188, 348-355. https://doi.org/10.1016/j.drugalcdep.2018.04.019 (Original work published 2018)