Later, he wrote on the history of the field with An Introduction to the History of Mycology (1976), An Introduction to the History of Plant Pathology (1981), and An Introduction to the History of Medical Mycology in 1986.
Senare författade han arbeten om mykologins historia: An Introduction to the History of Mycology (1976), An Introduction to the History of Plant Pathology (1981) och An Introduction to the History of Medical Mycology (1986).