Association of race and age with treatment attendance and completion among adult marijuana users in community-based substance abuse treatment. 

Peters EN, Hendricks PS, Clark CB, Vocci FJ, Cropsey KL (2014). Association of race and age with treatment attendance and completion among adult marijuana users in community-based substance abuse treatment. Journal of Addiction Medicine. 8(2):143-9. PubMed PMID: 24603621.