HELP: I need some references about " Kinds of computers"

Hello everyone . I have a seminar to do and I'm about to graduate. My seminar is about "kinds of computer" and as u know, computer classified into four categories according to its size and it's performance efficiency, Supercomputer, mainframe computer, mini-computer and micro-computer.


I need to find some good references that can help me to find deep informations for my seminar and particularly about supercomputer and mainframe computer.


I'll be grateful.
^_^