From the theoretical part of this review, one may notice that the features of FOs are governed by a set of parameters that may be used to fit the experimental observations into a theoretical model. Parameters of FOs include Fermi wavelength(λF ), periodicity, and Fermi wavevector (kF ). Period of oscillations is actually connected to the Fermi wavelength, being half of its numerical value. The former may be directly inferred from the STM images. However, that is under the assumption that low bias voltage and temperature are used to make the oscillations visible.