Stumbling Block Four - Web Site Errors

I encountered problems trying to access additional web-sites from http://www.mc.maricopa.edu/~rrodrigo/lessons/process/workshopping.htm for Deadline #5 - Reading Assignment(s).

I received errors on the first three links as follows:

The first link is displaying: 404 Error: Page Not Found - both when I click the link and when I copy and paste the link into Firefox or IE.
(http://www.mc.maricopa.edu/%7Errodrigo/peer_review/peer_review_guidelines.htm)

The second link is displaying: The page cannot be found error.
(http://www.wwnorton.com/we/ch1/5b.htm)

Perhaps the link changed - Maybe this is the correct link? (http://www2.wwnorton.com/college/english/write/we/ch1/5b.htm)

The third link is displaying: Error Occurred While Processing Request.
(http://writing.colostate.edu/references/teaching/co300man/pop18b.cfm)

The good news is the fourth link works! Yeah!

I sent an email to the professor for further assistance and clarification.