1. Hippocrates: The book of prognostics,1849
2. The Hippocratic fingers;Campbell;Brit. M. J.,1924
3. Caelius Aurelianus: On chronic diseases,1950
4. The morphology of clubbing;Bigler;Am. J. Path.,1958
5. Some observations on clubbed fingers;Mendlowitz;Clin. Sc.,1937