52 (3): 211–215. doi:10.3177/jnsv.52.211. ↑ Postlethwaite, A. E.; Seyer, J. M.; Kang, A. H. (1978). "Chemotactic attraction of human fibroblasts to type I, II, and III collagens and collagen-derived peptides". Proceedings of the National Academy of Sciences of the United States of America.