Dear Dr Bor,
I may be able to assist in your search. I am aware of at least one
official paper on the subject, and may be able to provide some other
hard data as well. You may contact me directly... skyrage_at_compuserve.com
or msheffer_at_wbtv.com ... I hope that I can be of service.
Regards-
Mike Sheffer
You may wish to review...... http://members.aol.com/safeflt/skyrage.htm