Cincinnati: Ohio Valley Co. pp. 1114–1117, see Lactuca.—Lettuce and Tinctura Lactucarii (U. S. P.)—Tincture of Lactucarium.{{cite book}}: CS1 maint: multiple names: authors list (link) ↑ "Lettuce opium". Retrieved 2007-05-28. 1 2 3 Wesołowska A, Nikiforuk A, Michalska K, Kisiel W, Chojnacka-Wójcik E (September 2006).