Surdellina (f)
(with) definite article: laFrom Paulo Maria Terzago, »Mvsevm septalianvm Manfredi Septalæ […] Pavli Mariæ Terzagi …« (Dertonæ [Tortona], 1664); Spelling also in Baines, who oddly refers to Scarabelli, who wrote the Italian version of Terzago’s book, but consistently uses the plural form of Sordellina (➺ link below [sources]); NB: ➺ homonyms & similar terms, Sardellina & Sardëllina, Serdellina, Sordelina &c., and Sourdeline and related terms.
Baines, Anthony: Bagpipes [1960]. Oxford, 1973 (revised), p.133 (6 surdelline: »Scarabelli/Julius [von] Schlosser [?]).
Meer, John Henry van der: Typologie der Sackpfeife. In: Anz. Germ. Nationalmus. (Nürnberg, 1964), p.134 (Surdelline [plural]: »Terzaghi [= Terzago]).
Meer, John Henry van der: Beitrag zur Typologie der westeuropäischen Sackpfeifen. In: SIMP I (Stockholm, 1969), p.106 (Surdellina).