“The Sequence of the Introduction of Crisis Management System Based on Diversification of Activities of Service Sector Enterprises”, Ekon. čas. Volins. nac. unìv. ìm. Lesì Ukraïnki, vol. 4, no. 4, pp. 54–57, Dec. 2015, doi: 10.29038/2411-4014-2015-04-54-57.