Bibliometric research often focuses on the extreme levels of granularity. On the one hand, it focuses on the analysis of individual papers, from the other discussing the features of the entire citation network, losing an intermediate stage of the achievements of one scientist. During the talk, I will try to present the known models of such track records. We will consider how to construct the models and assess their fit with empirical data. In conclusion, we will consider practical decisions which result from the implementation of such models.