Phone: 48 515 174 922, Fax: 48 71 328 36 96We dedicate this work to the memory of our collaborator Stephane Bonifacie, who died suddenly of a heart attack at the age of 32. Stephane was an exceptionally competent and gentle person. He greatly contributed to the subject of this paper by doing decisive work on the magneto-photoluminescence in GaAs/GaAlAs asymmetric quantum wells reported in our Ref. [14]. Stephane's untimely departure has been an irreparable loss to everybody who knew him. Article 250 W. Zawadzki et al.: Reservoir model for 2DEGs in quantizing magnetic fields ß Article 254 W. Zawadzki et al.: Reservoir model for 2DEGs in quantizing magnetic fields ß Article 258 W. Zawadzki et al.: Reservoir model for 2DEGs in quantizing magnetic fields ß Article 260 W. Zawadzki et al.: Reservoir model for 2DEGs in quantizing magnetic fields ß