This business trip (founded by the Spanish part) to Valencia, Spain was performed during December 2nd - 6th, 2019. The receiving institution was Universitat Politecnica de Valencia (UPV), Institute for Multidisciplinary Mathematics, Valencia, Spain. I presented there two mathematical models (in form of deterministic ODE system) for both students and academic staff. Then we discussed the possibility to formulate them as stochastic differential equations.