The isothermal slow plane flow of a viscoplastic strip under rolling is considered. The Prandtl friction law is assumed to be valid on the contact surface between the strip and the roller. Integral equations are found for possible tangential velocity disturbances in the lag zone and normal velocity disturbances on the free boundary for the special stationary flow of a strip at any time moment.Keywords: slow flow of a viscoplastic strip under rolling, special stationary flow, possible disturbances of a special stationary flow, minimum entropy production.