Columbia subject headings:
Librettos--England--London--1778.
Operas--18th century--Librettos.
Vulcan (Roman deity)--Drama--Early works to 1800.
Harvard subject headings:
Librettos.
Operas--England--18th century--Librettos.
Vulcan (Roman deity)--Drama--Early works to 1800.
Princeton subject headings: