Henck, J. B. (1896). Field-book for railroad engineers: Circular and parabolic curves, turnouts, vertical curves, levelling, computing earth-work, transition curves on new lines and applied to existing lines, together with tables of radii, ordinates, long chords, logarithms, logarithmic and natural sines, tangents, etc., and a metric curve table (2d rev. ed.). D. Appleton and company.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিHenck, John B. Field-book for Railroad Engineers: Circular and Parabolic Curves, Turnouts, Vertical Curves, Levelling, Computing Earth-work, Transition Curves on New Lines and Applied to Existing Lines, Together with Tables of Radii, Ordinates, Long Chords, Logarithms, Logarithmic and Natural Sines, Tangents, Etc., and a Metric Curve Table. 2d rev. ed. New York: D. Appleton and company, 1896.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিHenck, John B. Field-book for Railroad Engineers: Circular and Parabolic Curves, Turnouts, Vertical Curves, Levelling, Computing Earth-work, Transition Curves on New Lines and Applied to Existing Lines, Together with Tables of Radii, Ordinates, Long Chords, Logarithms, Logarithmic and Natural Sines, Tangents, Etc., and a Metric Curve Table. 2d rev. ed. D. Appleton and company, 1896.