https://etd.adm.unipi.it/theses/available/etd-04032014-093613/unrestricted/Tesi_Carlo_Gerboni.pdf (Any fulltext)
Gerboni, C. (2014). Development of a 6 dof nonlinear helicopter model for the MPI Cybermotion Simulator. PhD Thesis, Università di Pisa, Pisa, Italy.