  Since the discovery of molecular resonances in $^{12}$C+$^{12}$C in the early
sixties a great deal of research work has been undertaken to study
$\alpha$-clustering and resonant effects of the fusion process at sub-Coulomb
barrier energies. The modified astrophysical $S^{*}$ factors of
$^{12}$C+$^{12}$C fusion have been extracted from direct fusion measurements at
deep sub-barrier energies near the Gamow window. They were also obtained by the
indirect Trojan horse method (THM). A comparison of direct measurements and the
THM, which elucidates problems in the analysis of the THM, is discussed in this
Letter to the Editor.
