1. Measuring Technological Change: Aircraft Turbine Engines;Alexander;Technol. Fore. Soc. Change,1973
2. The Search for Speed Under Sail, 1700–1855;Chappelle,1967
3. A General Approach to Measurement of the State of the Art and Technological Advance;Dodson;Technol. Fore. Soc. Change,1970
4. A Study of Technological Innovation—The Evolution of Digital Computers;Knight,1963