CREATE TABLE table_67357 ("Image" FLOAT, "Smith" TEXT, "Ashmolean" FLOAT, "Foster" FLOAT, "Hahland" FLOAT, "Dinsmoor" TEXT, "Hofkes-Brukker" TEXT, "Harrison" TEXT, "Cooper" TEXT, "BM/Corbett" TEXT)

What is the lowest image with a 20w Harrison, and less than 20 for Ashmolean?
SELECT MIN("Image") FROM table_67357 WHERE "Harrison" = '20w' AND "Ashmolean" < '20'
SELECT MIN("Image") FROM "table_67357" WHERE "Ashmolean" < '20' AND "Harrison" = '20w'