On Feb. 8 Mark Cobern asked about references to Gilbert & Sullivan.

The fullest discussion I know of is in H. Baetzhold, _Mark Twain and John
Bull:The British Connection_ (Indiana University Press, 1970) See the index
under Gilbert.  There are also a few references not contained therein in
Gribben, _Mark Twain's Library_ I, 258-259.
        HGB