1. Shape description if completely visible and partially occluded leaves for identifying plants in digital images;Franz;Transactions of the ASAE,1991
2. Application of machine vision to shape analysis in leaf and plant identification;Guyer;Transactions of the ASAE,1993
3. Computer vision for identifying weeds in crops;Hemming,2000
4. Identification of plants for wild flower garden;Katayama,1998
5. Bildverarbeitung interaktiv. [Interactive image processing;Kopp,1997