https://lviv.dotnet.city/2010/12/%d0%bf%d0%b0%d1%82%d0%b5%d1%80%d0%bd-%d0%b2%d1%96%d0%b2%d1%82%d0%be%d1%80%d0%ba%d0%b0-19-%d1%81%d1%82%d1%80%d0%b0%d1%82%d0%b5%d0%b3%d1%96%d1%8f-strategy/