Alvin -

"Mr. Clemens and Mark Twain," by Justin Kaplan has one reference to Bierce
which states that he hardly knew Twain (p. 119).

"The Inventions of Mark Twain," by John Lauber contains one reference to
Bierce in which he expresses his view that Twain "the jester is Mark the
Money-worm" (p. 260). This was in response to a speech by Twain in which he
plugged the Paige typesetter.

This is not much, but it may be a start. My view is that they were too much
alike to have been able to stand one another for long if they did ever get
together.

I would be interested in hearing anything you find out as I have been trying
to locate some scholarly texts on Bierce myself.

Marc Koechig