1) Ltie, H., Theilade, E. and Jensen, S. B.: Experimental gingivitis in man. J. Periodontol., 36: 177-187, 1965
2) Keistrup, J. and Theilade, E.: Microbes and periodontal disease. J. Clin. Periodont., 1: 15-35, 1974.
3) Socransky, S. S.: Microbiology of periodontal disease-Present status and future consideration-. J. Periodontol., 48: 497-507, 1977.
4) Theilade, E., Wright, W. H., Jensen, S. B. and e, H.: Experimental gingivitis in man 2L. oA longitudinal clinical and bacteriological investigation. J. Periodont. Res., 1: 1-13, 1966.
5) Socransky, S. S.: Relationship of bacteria to the etilolgy of periodontal disease. J. Dent. Res., 49: 203-222, 1970