What kind of information would the author of The
Riddle of the Rosetta Stone have found useful in this
reference?

This is a reference entry from The Riddle of the Rosetta
Stone:
Frimmer, Steven. The Stones That Spoke: And
Other Clues to the Decipherment of Lost
Languages. New York: G. P. Putnam's Sons,
1969.

O which stones have hieroglyphics written on them

o who the Egyptian pharaohs were

how the Rosetta Stone provided clues to
hieroglyphics

O which languages are spoken today