My professor introduced in the last lesson a new method for clock synchronisation, which he called "Reichenbach synchronisation". In this new method, two clock A and B synchronise themself with the relation
$$ t_B = t_A + \varepsilon(t_A' -t_A) \qquad \varepsilon \in ]0,1[. $$
Where A emits a signal at time $t_A$, it arrives at B at time $t_B$ and then returns in A at time $t_A'$.
So he states that simultaneity is a conventional aspect of relativity, and then he start to develop the theory using these assumptions. My problem is that I can't find any reference for this theory, neither in textbooks neither in publications. Can you list me a bibliography for these arguments, and if possible, download link for research papers?