Brother's Keeper -a shareware product. There are also several other programs available and all are good for different things. When choosing a software program to use it is important to really understand what is the most important thing to you. To some, source information is very important, to others the amount of space available for notes and to others the most important thing might be the report capabilities. Before one selects a program always try and find a working demo by checking Internet Web Sites.
Most manufacturers have demos or at least detailed explanations of their programs.
There is a whole section devoted to DOS Software and one devoted to Windows Software. Compuserve also has a forum devoted to program support and answers are usually found there for most questions.