Alpatov, A., Kravets, V., Kravets, V. and Lapkhanov, E. 2021. Representation of the kinematics of the natural trihedral of a spiral-helix trajectory by quaternion matrices . Transactions on Engineering and Computing Sciences. 9, 4 (Jul. 2021), 18–29. DOI:https://doi.org/10.14738/tmlai.94.10523.