Does anyone know of a good, complete reference for non-commutative formal group laws (i.e. construction of a "Lazard ring," discussion of non-commutative formal groups, perhaps some discussion of their moduli stack)? I seem to recall being told that there were at least a few South American mathematicians doing some really nice work on this sort of stuff, but don't know their names and haven't been able to find it. Thanks for any references on this! :)