Dan O'Bannon's Guide To Screenplay Structure

'Dan O'Bannon's Guide to Screenplay Structure' by Dan O'Bannon and Matt R. Lohr (Michael Wiese Productions paperback 244-pages) 

An insightful and entertaining guide from a screenwriter of classics such as 'Alien' and 'Total Recall'. The book covers other writer's systems and provides structural analyses of many classic films to explore structures that work.