Page 227. " a large percentage of patients reported to the doctors and nurses that they saw someone standing at the end of their bed at night. "

This is a reference to the Angel of Death, which the medical students are told is not a supernatural vision but a delusion caused by the patients' medical conditions.

Page 229. " When will the love muffins be done, Mata Hari? "

Mata Hari was the stage name of Margaretha Geertruida Zelle MacLeod (1876–1917), one of the world's most popular exotic dancers, who found herself in Paris just before the outbreak of the First World War. Though the facts are not clear, she was thought to have become involved in the world of international spying, and was accused of espionage and executed by firing squad in 1917.