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- ^ Robert E. Powell, R. J. Weldon e Jonathan C. Matti, The San Andreas fault system, Geological Society of America, 1993, pp. vii, 5, 150, 151, ISBN 0-8137-1178-9.
- ^ a b Lal S. Mian, Inland Empire Environmental Quality Paradigm (PDF), San Bernardino, California State University, San Bernardino, Department of Health Science and Human Ecology, December 2000. URL consultato il 14 giugno 2018 (archiviato dall'url originale il 9 settembre 2006).
- ^ Liam H. Davis, McKernan, Robert L. e Burns, James S., History and Status of the California Gnatcatcher in San Bernardino County (PDF), in Western Birds, vol. 29, n. 4, Organization of Western Field Ornithologists, 1998, pp. 361–365. URL consultato il 14 giugno 2018.