1. Bekken, F. F., Simons, E. I., & Noteboom, F. (2021). Daders van binnenlandse seksuele uitbuiting [Offenders of domestic sex trafficking]. Centrum tegen Kinderhandel en Mensenhandel (CKM), the Netherlands. Retrieved April 17, 2023, from https://www.hetckm.nl/nieuws-en-publicaties/daders-van-binnenlandse-seksuele-uitbuiting/1
2. Blumstein, A., Cohen, J., Das, S., & Moitra, S. D. (1988). Specialization and seriousness during adult criminal careers. Journal of Quantitative Criminology, 4(4), 303–345. https://doi.org/10.1007/BF01065343
3. Blumstein, A., Cohen, J., Roth, J. A., & Visher, C. A. (1986). Criminal careers and “career criminals”: Volume 1. The National Academies Press. https://doi.org/10.17226/922
4. Bovenkerk, F., Van San, M., Boone, M., Boekhout van Solinge, T., & Korf, D. J. (2006). ‘Loverboys’ of modern pooierschap [‘Loverboys’ or modern pimping]. Augustus, the Netherlands.
5. Cale, J., Smallbone, S., Rayment-McHugh, S., & Dowling, C. (2016). Offense trajectories, the unfolding of sexual and non-sexual criminal activity, and sex offense characteristics of adolescent sex offenders. Sexual Abuse, 28(8), 791–812. https://doi.org/10.1177/1079063215580968