Let's move away from discussing the two-dimensional electron gas system, which includes graphene, and focus instead on the cause of the oscillations. We'll see that this system can also be perturbed by a magnetic field. Their FO results seem to be valid for a wide range of physical parameters such as potential strength, magnetic field, and distances.purity in 2D electron systems within non-zero magnetic field. Rusin and Zawadzki 137 presented an analytic procedure using the exact renormalised single-particle Green's function obtained via summation of the corresponding Dyson series. They showed first validity of the procedure on a simple example of 2D free electron gas, and later on employed it for two cases: (1) monolayer graphene and (2) group-VI dicalchogenides. Their FO results seem to be valid for wide ranges of physical parameters such as potential strength, magnetic field and distances. It appears that for weak impurity potentials, the amplitude of FO are proportional to the impurity potential strength. However, they also found that given a specific set of parameters, the total charge density becomes negative, contradicting the electric neutrality of the whole system -therefore, their single-particle procedure has limitations, and in the aforementioned case, the interacting fermionic system should be used instead.