Johnson, Matthew C. and Kamionkowski, Marc (2008) Dynamical and gravitational instability of an oscillating-field dark energy and dark matter. Physical Review D, 78 (6). Art. No. 063010. ISSN 1550-7998 http://resolver.caltech.edu/CaltechAUTHORS:JOHprd08 <http://resolver.caltech.edu/CaltechAUTHORS:JOHprd08>