Characterization of growing lettuce from density contours–I. Head selection. - T. F. Schatzki; S. C. Witt; D. E. Wilkins; D. H. Lenker (Pattern Recognit., 1981)

Characterization of growing lettuce from density contours–II. Statistics. - T. F. Schatzki; S. C. Witt; D. E. Wilkins; D. H. Lenker (Pattern Recognit., 1981)