Sandweiss, D. H., Maasch, K. A., & Burger, R. L. (2001). Variation in Holocene El Niño frequencies: Climate records and cultural consequences in ancient Peru. Geology, 29(7), 603. https://doi.org/10.1130/0091-7613(2001)029<0603:VIHENO>2.0.CO;2
Chicago Style (17th ed.) CitationSandweiss, Daniel H., Kirk A. Maasch, and Richard L. Burger. "Variation in Holocene El Niño Frequencies: Climate Records and Cultural Consequences in Ancient Peru." Geology 29, no. 7 (2001): 603. https://doi.org/10.1130/0091-7613(2001)029<0603:VIHENO>2.0.CO;2.
MLA (9th ed.) CitationSandweiss, Daniel H., et al. "Variation in Holocene El Niño Frequencies: Climate Records and Cultural Consequences in Ancient Peru." Geology, vol. 29, no. 7, 2001, p. 603, https://doi.org/10.1130/0091-7613(2001)029<0603:VIHENO>2.0.CO;2.