Bygdeman, S, I Kallings, and D Danielsson. 1981. “Serogrouping and Auxotyping for Epidemiological Study of Beta-Lactamase-Producing Neisseria Gonorrhoeae Strains Isolated in Sweden”. Acta Dermato-Venereologica 61 (4):329-34. https://doi.org/10.2340/0001555561329334.