Thanks again Alex; I appreciate all of your helpful advice. I apologize for getting so far ahead of myself; I have to keep in mind that my interests are leading me along a mathematical marathon rather than a sprint. String Theory is another of my areas of interest, but I realize I am a long way from there at this point. If anyone else is interested, there is a great site at www.superstringtheory.com which has a lot of valuable information. In the meantime I'll look forward to more intriguing postings at CTK Exchange. Keep up the good work! :)