The contents of this publication are intended for providing additional supplementary materials, i.e. proofs of formula derivations, presented in our paper entitled "An Analytical Study of Time of Flight Error Estimation in Two-Way Ranging Methods". The mentioned paper was submitted to ``Ninth International Conference on Indoor Positioning and Indoor Navigation (IPIN) 2018}'', which will be held in Nantes, France on September 24-27, 2018.