Madrid: Antonio Romero n.d.
Public Domain [tag/del]
||Instruccion teoretico practico per el pito de mando
||Manual for the one-valved whistle
||Marzo y Feo, Enrique
||pito de mando (one-valved whistle)
A curiosity. The pito de mando was a newly invented whistle for signalling for military and police use, capable of 5 different pitches. See picture on p 11.