1. . , , et al: Sacroiliitis in eight populations. Excerpta Medica International Congress Series No. 14, 1966, pp 293–298
2. . : The Frequency of the Rheumatic Diseases. Cambridge, Harvard University Press, 1971, pp 105–114
3. . : Report from the subcommittee on diagnostic criteria for ankylosing spondylitis. Excerpta Medica International Congress Series No. 148, 1966, pp 314–316
4. . : Hereditary factors in rheumatoid arthritis and ankylosing spondylitis, The Epidemiology of Chronic Rheumatism. Vol 1. Edited by . . Oxford, Blackwell Scientific Publications, 1963, pp 258–266