http://historyreviewed.best/index.php/when-russians-kill-russians-the-inhumane-russians-the-very-nasty-concept-of-a-blocking-force-chechen-blocking-units-in-ukraine/
WHEN RUSSIANS KILL RUSSIANS: The Inhumane Russians: The very nasty concept of a Blocking Force! - Chechen Blocking Units in Ukraine