Stamp them Missing in Reaction. These books may be hard to find-special- interest groups are pressuring libraries to remove them from shelves. *IN THE NIGHT KITCHEN Maurice Sendak Why: Reading the book ''could lay the foundation for future use of pornography.'' -Elk River, Minn.
*THE ADVENTURES OF HUCKLEBERRY FINN Mark Twain Why: ''Racist language,'' including the word nigger. -Modesto, Calif.
*A LIGHT IN THE ATTIC Shel Silverstein Why: A poem in which a girl dies of a broken heart is ''morbid.'' -West Mifflin, Pa.
*SNOW WHITE The Brothers Grimm Why: Graphic violence: A hunter kills a wild boar; a witch orders Snow White's heart torn out. -Duval, Fla.