You can study the full video course directly via the TheChessWorld Store or explore purchasing options at USCF Sales. 📘 Course Breakdown: Closed Catalan for Black
If you want to view free introductory lessons by Andrey Ostrovskiy before getting the masterclass, you can check out his public material: Watch the Closed Catalan Opening Basic Plans on Lichess . Watch the Open Catalan Opening Basic Plans on Lichess . Catalan System For Black With Andrey Ostrovskiy...
This 7-hour course by International Master Andrey Ostrovskiy is designed to teach Black how to dismantle White's Catalan setups. You can study the full video course directly