The review deals with different external fields, the sources of which are contained in the matter of collapsing systems. An analysis is presented of papers, according to which scalar, meson, and neutrino fields vanish outside the black holes. In this connection, a number of questions are formulated, to which there is still no definite answer. It is assumed that exhaustive answers to these questions will be obtained when matchable external and internal solutions can be found for all these cases. At the present time the analysis of this problem is based mainly on considering the external solution and the hypothesis that a horizon exists and perturbation theory is applicable.