The first known Greek medical school opened in Cnidus in 700 BC. Alcmaeon, author of the first anatomical work, worked at this school, and it was here that the practice of observing patients was established. Hippocrates established his own medical school at Cos. Despite their known respect for Egyptian medicine, attempts to discern any particular influence on Greek practice at this early time have not been dramatically successful because of the lack of sources and the challenge of understanding ancient medical terminology. It is clear, however, that the Greeks imported Egyptian substances into their pharmacopoeia, and the influence becomes more pronounced after the establishment of a school of Greek medicine in Alexandria.