This was a most impressive response - I appreciate your very fast response and apologize for taking so long to acknowledge - although I already had some of your references I would probably not have found others, especially the one from Jusserand. Thank you very much - good job!!! 

 This was exactly what I needed, and he provided additional information which I found interesting as well. Thanks clouseau! 

 Clouseau was a true professional; he assisted through a very hard question, and responded quickly and helpfully.