an Entity references as follows:
Anton de Haen (December 8, 1704 – September 5, 1776) was an Austrian physician of Dutch ancestry born in the Hague. He studied medicine in Leiden under Hermann Boerhaave, and in 1754 went to the University of Vienna, where he became head of its medical clinic. He is remembered for teaching students at the bedside of patients. Among his written works was Ratio medendi in nosocomio practico, of which 18th century Viennese hospital practices and case histories are discussed. This treatise also described one of the earliest known cases of amenorrhea associated with a pituitary tumor.