If you have not used Western's digital library before, you may have difficulty downloading the papers. If you are working from a computer with a Western IP address, then access should direct. However, if you are using a computer with a non-Western IP address, then you will most likely need to use the library's proxy server to access the papers. The login page for it is at http://www.lib.uwo.ca/. If you have trouble with that, either use the Library's help chat feature to find out what the difficulty is or visit the information desk at any of the University libraries.
Note: the verification and validation paper also talks about confidence intevals. To get a sense of what it will mean to calculate them using R, look at 9. Calculating confidence intervals.