I know of no sites offhand, but a good book along these lines is:
DECORATIVE ART OF THE SOUTHWESTERN INDIANS
DOROTHY SMITH SIDES
ORIGiNALLY PUBLISHED 1936
Sometimes a librarian will help you get images via scanners, and if you can get images and post here I can consult my copy. You may be able to get a copy of this book via inter-library loan, the librarians are very helpful, most everywhere. If the rug is from another area and not the
Southwest, then I can't help directly, but again, the library will. Good Luck, and I am including a representation from the book, just for fun, of a Navajo sand painting from the 1880's, depicting graphically a Pheasant Tailed Comet.
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