López MV, Rivero E, Serra C, Campo M, Raurich M, Bonfill X. Health survey in health care professionals in Barcelona. Arch Prev Riesgos Laborales. 1998;1(2):55-62.
Lawson DH, Jick H, Rothman KJ. Coffee and tea consumption and breast disease. Surgery. 1981 Jan 1;90(5):801-3.