URL
http://vbrant.eu/sites/vbrant.eu/files/Stoev_et_al_2013_Editorial_revolving_gonopods.pdf
http://www.pensoft.net/journal_home_page.php?journal_id=1&page=article&SESID=bb44f46bc3cac09981bbfa99622b8aae&type=show&article_id=5763
http://www.pensoft.net/journals/zookeys/article/1291/a-review-of-the-millipede-genus-sinocallipus-zhang-1993-diplopoda-callipodida-sinocallipodidae-with-notes-on-gonopods-mo
http://www.pensoft.net/journal_home_page.php?journal_id=1&page=article&type=show&article_id=504&abstract=1