Diniz, R. E. A. S.; Goldenberg, J.; Carvalho, J. C. M. de; Gomes, C. E. S.; Goldenberg, E. D.; Sementille, A. Lymphoma of Unknown Origin Located in Paravertebral Muscles: An Unusual Cause of Low Back Pain in Children. Sao Paulo Med J 1995, 113, 953-956.