GUZIY, S., SHLYAPNIKOV, A., HUDEC, René. CCD observations of the QSO 4C49.29 in the error box of GRB960720. In: KIPPEN, R.M., MALLOZZI, R.S., FISHMAN, G.J., eds. Gamma-ray bursts. Melville: American institute of physics, 2000, s. 339-341. AIP conference proceedings., 526.