Eichbaum, G. R., & Twining, A. C. 1. (1849). Report of the chief engineer on the location and estimates of cost of the Cleveland and Pittsburgh Railroad: Accompanied by the report of Prof. Alexander C. Twining, consulting engineer, and the statement of the president and directors to the stockholders of the company. Hudson [OH]: Observer Press.

Eichbaum, George R., and Alexander C. 1801-1884 Twining. Report of the Chief Engineer On the Location and Estimates of Cost of the Cleveland and Pittsburgh Railroad: Accompanied By the Report of Prof. Alexander C. Twining, Consulting Engineer, and the Statement of the President and Directors to the Stockholders of the Company. Hudson [OH]: Observer Press, 1849.

Eichbaum, George R., and Alexander C. 1801-1884 Twining. Report of the Chief Engineer On the Location and Estimates of Cost of the Cleveland and Pittsburgh Railroad: Accompanied By the Report of Prof. Alexander C. Twining, Consulting Engineer, and the Statement of the President and Directors to the Stockholders of the Company. Hudson [OH]: Observer Press, 1849.