Marimba: Brief Description — Vienna Symphonic Library
“The marimba looks almost exactly the same as the xylophone, but is larger, has a lower register (from bass through tenor to alto) and a wider compass. It is a xylophone with resonators – xylo-phon simply means "wood sounder" – pitched an octave deeper.”
Marimba: Instrument Guide — Yamaha
“There are various ingenious ways in which the marimba is designed to produce musical notes, including in places you cannot see, as well as through the length and thickness of the wood.”
Keyboard Percussion: Instrument Studies for Eyes and Ears — Jacobs School of Music
Instrument Studies for Eyes and Ears, by Don Freund, site designed by Reid Merzbacher
Percussion: The Orchestra: A User's Manual — Andrew Hugill
“The aim of The Orchestra: A User's Manual is to provide information about the orchestra, orchestration, composition and instruments, for the benefit of anybody with an interest in the subject.”