This post shows you example code of how to select entire By Groups of data in SAS conditional on criteria on single observations.
Have you ever been stuck on a SAS problem and not even Google seems to be of help? Fear not! Help is on the way in the SAS online communities.
Learning SAS programming, I like to learn new stuff and to learn more about the subjects I am already familiar with. SAS books is a great way to do this. Here are the SAS books on my shelf.