1. Haas DC. Chronic post-traumatic headache. In: Olesen J, Tfelt-Hansen P, Welch KMA, eds. The headaches. New York: Raven Press, 1993:609-637.
2. Pereira Monteiro JM, Maio RJ, Calheiros JM. Headaches diagnosis: comparison of questionnaire with clinical interview. In: Olesen J, ed. Headache classification and epidemiology. Frontiers in headache research. New York: Raven Press, 1994:315-320.