The rook (Corvus frugilegus L.), its nesting in the Slovakia and relationship towards agricultural land / Jana Porhajašová, Dávid Ernst, Alena Rakovská. -- grafy, ilustr. -- Bibliografické odkazy. In: Research journal of agricultural science. -- ISSN 2066-1843. -- Vol. 47, no. 1 (2015), s. 174-182. havran čierny * hniezda * monitorovanie * biotopy * ohrozené druhy * Slovensko