I have done a measurement at a HgTe 2DEG. I have measured nice plateaus in Rxy and Shubnikov de Haas Oscillations in Rxx. In the B field range between 1 and 3 Tesla I see some variation in the Shubnikov de Haas oscillations compared to bigger magnetic fields. One minimum is not so deep and the next is deeper then the next one is less deep the next one deeper again. What is the reason for this?