In the present review of the author's works, the calculation of the radiation spectrum of a hydrogen-like atom is described in detail using the principle of commensurability of conserved quantities, which is introduced by the author. The result obtained allows us to give a clear physical interpretation of Bohr's quantum hypothesis. It follows from the data obtained that the “resolved” states of quantum systems are the result of the need to fulfill the requirement of having a common measure of conserved quantities for all participants in physical interaction before and after interaction.