We show that the equivalence between the c=1 non-critical bosonic string and
the N=2 topologically twisted coset SL(2)/U(1) at level one can be checked very
naturally on the level of tree-level scattering amplitudes with the use of the
Stoyanovsky-Ribault-Teschner map, which recasts H3+​ correlation functions
in terms of Liouville field theory amplitudes. This observation can be applied
equally well to the topologically twisted SL(2)/U(1) coset at level n>1, which
has been argued recently to be equivalent with a c<1 non-critical bosonic
string whose matter part is defined by a time-like linear dilaton CFT.Comment: harvmac, 22 pages; v2 typos corrected, version appearing in JHE