Please refer to the updated version of the General Habitat Classification System (ÁNÉR), edited by János BÖLÖNI, Zsolt MOLNÁR and András KUN. "Magyarország élőhelyei; Vegetációtípusok leírása és határozója (Habitats of Hungary; Descriptions and Identification Keys of Vegetation Types of Hungary) - ÁNÉR 2011", Institute of Ecology and Botany, Hungarian Academy of Sciences, Vácrátót, Hungary, 2011 (in Hungarian).
The full chapter of the 'OA' habitat type
Distribution map of the 'OA' habitat from the ÁNÉR 2011 textbook: