Multiple HPV infections with high viral loads are associated with cervical lesions but do not differentiate grades of cervical abnormalities, Schmitt, M., Depuydt C., Benoy I., Bogers J., Antoine Jérôme, Arbyn M., and Pawlita M. , J.Clin.Microbiol., 27/2/2013, Volume 51, Issue 5, Number 1464, p.1458 - 1464, (2013)