The 1998 Grolier Multimedia Encyclopedia (TM) copyright (c) 1997 by Grolier Interactive Inc.
Articles: 'Cloud' by Roger A. Pielke
'Cumulonimbus Clouds' by Roger A. Pielke
'Stratus clouds' by Roger A. Pielke

Engelbert, Phillis The Complete Weather Resource Volume1: Understanding Weather, An Imprint of Gale, Copyright 1997

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