I am seeking a copy of the MathCAD Plus 6.0 Professional Edition User’s Guide, new, used or digital format.
There are many user guides for this application. The only requirement is that you'll have to use Google to obtain them. Access Google Search results and click on websites that have [PDF] at the beginning of the title. A compatible PDF reader is required in order to open the file. You can find one using the database of Software Informer. You can use Adobe Reader if you don't want to search for one.