1) Attwood, H. D. and Park, W. W.: Embolism to the lung by trophoblast, J. Ob. & Gy., 68: 611 617, 1961.
2) Dahlin, D. C. and Salvador, A. H.: Chondrosarcoma of bones of the hands and feet-A study of 30 cases, Cancer, 34: 755-760, 1974.
3) Dalen, J. E., Alpert, J. S.: Natural history of pulmonary embolism, Progress in Cardiovasc. Dis., XVII: 259-270, 1975.
4) Evans, H. L., Ayala, A. G., Romsdahl, M. M.: Prognostic factors in chondrosarcoma of bone-A clinicopathologic analysis with emphasis on histologic grading, Cancer, 40: 818-831, 1977.
5) Henderson, D. W. and Papadimitriou, J. M.: Ultrastructural appearances of tumors, a diagnostic atlas, p.250-269, Churchill Livingstone, London, 1982.