I have used Linda Cowgill's book, Writing Short Films, for a three-hundred level course, which I have taught at the University of Arizona, for over four years. It continues to be an excellent basic text for my students even though I have read many of the other books on the market. Linda defines all the important tools of a writer and their uses within the craft. She uses many short films in the book to exemplify her points directly and easily. The short films are excellent references and are accessible for showing--which is a perfect visual teaching tool. Even though the title is for short scriptwriting, she talks about full length films in comparison and, of course, all of these elements and tools are equally important for the full length form. It remains my favorite reference book for my own writing of screenplays and recommend it as the best of the screenwriting books on the market.