Well, what a brave enterprise!  One which of course every viola player
should applaud as we have more obscure (sorry, unjustly neglected)
repertoire than anyone else.  Ten minutes with Grove gave these which
might help:

Abelard
Abel ('on the Abel label')
Anderson?
Absolute
Accidental
Accordo
Ad libitum
Aeolian
Alba
Al fine
Alto/a/us
Amadeus
Amati

Even if none are right they might set your mind going in the right
direction.  Let me know how you get on.

Best wishes,
Paul