Further Studies in Transportation-Markings is Volume II of Transportation-Markings: A Study in Communication Monograph Series. Volume in this instance is an organizational device that brings together four separate monographs. It is not a book title. The monographs of the Series are arranged in volumes according to chronology or topic.
Further studies originally included first editions of the monographs:
| E. International traffic control devices (1st edition, 1984)
| F. International railway signals (1st edition, 1991)
| G. International aeronautical navigation aids (1st editions, 1994)
| H. A general classification of international transportation markings.(1st edition, 1994)
International Traffic Control Devices has a 2nd edition, 2004. T-M General Classification (a revised title) has a 2nd edition, 2003, and a 3rd edition, 2010.