Pero (n)
Tongue of the reed; Studena.
Širola, Božidar: Sviraljke s udarnim jezičkom [Aerophones with a beating tongue]. Zagreb, 1937, p.126, 158, 224.
Gojković, Andrijana: Narodni muzički instrumenti [Folk musical instruments]. Beograd, 1979 (1: »Širola [129]).