Crowley، J. L.؛ Parker، A. C. (مارس 1984). "A representation for shape based on peaks and ridges in the difference of low-pass transform". IEEE Transactions on Pattern Analysis and Machine Intelligence. ج. 6 ع. 2: 156–170. DOI:10.1109/TPAMI.1984.4767500. PMID:21869180.
Crowley، J. L.؛ Parker، A. C. (مارس 1984). "A representation for shape based on peaks and ridges in the difference of low-pass transform". IEEE Transactions on Pattern Analysis and Machine Intelligence. ج. 6 ع. 2: 156–170. DOI:10.1109/TPAMI.1984.4767500. PMID:21869180.