The sine is often neglected; for a correct treatment see: "Validation of a Mathematical Model for Road Cycling Power" by James C. Martin et al., Journal of Applied Biomechanics, Volume 14, Issue 3, August 14, 1998, pp.276 – 291 [1]
"Bicycle statistics". City of Copenhagen website. City of Copenhagen. 13 June 2013. Archived from the original on 12 December 2013. Retrieved 12 December 2013.
"Bicycle statistics". City of Copenhagen website. City of Copenhagen. 13 June 2013. Archived from the original on 12 December 2013. Retrieved 12 December 2013.