Otvor (m)
opening (for the valve) in the cheek of the bellows
Hole in the lower cheek of the bellows, with a non-return inlet-valve on the inside; On the outside fitted with a "fence" protecting the piper’s clothes; Ždralovi.
Širola, Božidar: Sviraljke s udarnim jezičkom [Aerophones with a beating tongue]. Zagreb, 1937, p.203 (»Križan).