Physiologische Übungen und Demonstrationen: für Studierende By Robert Tigerstedt. Published by Taylor & Francis , 1913. Page 186.
From: Endocrinology and Metabolism. Llewellys Barker, MD, editor. Published 1922. Chapter: The normal process of energy metabolism, John R. Murlin. Page 532.
The diverse, quirky and mostly forgotten history of Pulmonary Function testing