கேள்வி: உருள் எதிர்திறன் - குறிப்புகள் பற்றி தகவல் சொல்.
பதில்: *Астахов П.Н. "Сопротивление движению железнодорожного подвижного состава" (Resistance to motion of railway rolling stock) Труды ЦНИИ МПС (ISSN 0372-3305). Выпуск 311 (Vol. 311). - Москва: Транспорт, 1966. – 178 pp. [http://oskicat.berkeley.edu/record=b12003170~S1 perm. record at UC Berkeley] (In 2012, full text was on the Internet but the U.S. was blocked) *Деев В.В., Ильин Г.А., Афонин Г.С. "Тяга поездов" (Traction of trains) Учебное пособие. - М.: Транспорт, 1987. - 264 pp. *Hay, William W. "Railroad Engineering" New York, Wiley 1953 *Hersey, Mayo D., "Rolling Friction" ''Transactions of the ASME'', April 1969 pp.&nbsp;260–275 and ''Journal of Lubrication Technology'', January 1970, pp.&nbsp;83–88 (one article split between 2 journals) Except for the "Historical Introduction" and a survey of the literature, it's mainly about lab. testing of mine railroad cast iron wheels of diameters 8" to 24" done in the 1920s (almost a half century delay between experiment and publication). *Hoerner, Sighard F., "Fluid dynamic drag", published by the author, 1965. (Chapt. 12 is "Land-Borne Vehicles" and includes rolling resistance (trains, autos, trucks). *Roberts, G. B., "Power wastage in tires", International Rubber Conference, Washington, D.C. 1959. *U.S National Bureau of Standards, "Mechanics of Pneumatic Tires", Monograph #132, 1969-1970. *Williams J A, "Engineering tribology" Oxford University Press, 1994.