We have noticed several experimental papers showing a hint of the theoretical explanation, yet usually, it seems too short (to the point of not being understandable) and quite vague. Silkin's book chapter 140 provides a much better description of the methods than the papers alone, , but the employed physical model seems to be questionable. For the latter, the floating 2D electron gas above the half-infinite 3D metallic bulk has been considered, and the reproducibility level seems quite low due to the high dependence on the system's pseudopotential. Riechers et al. have shown the experimental potential and sense of probing the FOs in the 1D ultra-cold fermionic gas, yet that is more of a conceptual study (or the data-analysis method proposal) rather than the actual theory or experiment. Furthermore, Khotkevych et al. have shown the real application of those FOs in terms of the proper STM imagining -that is e.g. the real-space image of FOs should not be considered while trying to obtain the Fermi line or that even the STM tip also may induce oscillations on the investigated sample.