You can check our primer set for ampifying the most informative regions for both HPV6 and HPV11. Table S2 in Clin Microbiol Infect (2013), Godínez et al "Phylogenetically related, clinically different: human papillomaviruses 6 and 11 variants distribution in genital warts and in laryngeal papillomatosis". DOI 10.1111/1469-0691.12420