A brief and transparent derivation of the Lorentz-Einstein   transformations via thought experiments
  Starting with a thought experiment proposed by Kard, which derives the formula that accounts for the relativistic effect of length contraction, we present a "two line" transparent derivation of the Lorentz-Einstein transformations for the space-time coordinates of the same event. Our derivation make uses of Einstein's clock synchronization procedure 
Bernhard Rothenstein, Stefan Popescu, and George J. Spix