Green Soup - Using flour, cream, lettuce, spinach, and watercress with stock. - http://www.cs.cmu.edu/~mjw/recipes/soup/green-soup.html
Braised Lettuce Soup - From The Thorough Good Cook. Recipes by George Augustus Sala from 1896. - http://www.eatdangerously.com/thorough_cook/soups/braised_lettuce_soup.html
Lettuce Soup - Recipe from Abbeydale House Bed and Breakfast, Surrey, British Columbia, Canada. - http://www.virtualcities.com/ons/bc/w/bcw77012.htm
Cream of Lettuce Soup - Contains butter, cornstarch, milk, sugar, and onion. - http://www.foodfunandfacts.com/creamoflettucesoup.htm
Zuppa D' Erbe (Lettuce Soup) - Contains stock, sorrel, endive, chervil, carrot and parmesan. - http://www.worldwideschool.org/library/books/tech/recipes/soup/Zuppad'Erbe/Chap0.html