1. Tattooed Skin and Health
2. A medical-toxicological view of tattooing
3. Microbial status and product labelling of 58 original tattoo inks
4. Council of Europe Resolution ResAP(2008)1 on requirements and criteria for the safety of tattoos and permanent make-up (superseding Resolution ResAP(2003)2 on tattoos and permanent make-up) 2008 http://www.coe.int/t/e/social_cohesion/soc-sp/resap_2008_1%20e.pdf
5. E. Jacobsen K. Tønning E. Pedersen N. Bernth J. Serup T. Høgsberg E. Nielsen Chemical Substances in Tattoo Ink http://www2.mst.dk/Udgiv/publications/2012/03/978-87-92779-87-8.pdf