Maybe the following paperpapers will be helpful:
http://iopscience.iop.org/0036-0279/29/5/A04/ (The ideas of N. N. Luzin in descriptive set theory, by L. V. Keldysh)
http://iopscience.iop.org/0036-0279/40/3/R06/ (Luzin's contribution to the descriptive theory of sets and functions: concepts, problems, predictions, by V.A. Uspenskii)