These are two of my anotated citations. They are in the Chicago style:
Alvarez, W. and E.G. Kauffman. Jan 1984. Impact theory of mass extinctions and the invertebrate fossil
record. Science. 223(4641): 1135-45. Available from GEOBASE (Geography) Database.
FirstSearch. October 2008.
Walter Alvarez, Erle Kauffman and others reviewed data from previous fossil digs at the K/T boundary from multiple locations where scientists concluded reasons other than extraterrestrial impact as probable cause for mass extinction. The evaluation examined the fossils of four groups of shelled invertebrates including: Ammonites, Cheilostomate byrozoans, Brachiopods, and Bivalves. The team concluded what they had suspected: that mass extinction at the end of the Cretaceous period; and, thus provides evidence which supports an extraterrestrial impact.
Alvarez, L.W. and W. Alvarez. Jun 1980. Extraterrestrial Cause for the Cretaceous-Tertiary Extinction.
Science. 208(4448): 1095-108. Available from JSTOR Database. JSTOR. October 2008.
Luis Alvarez, Walter Alvarez and others preformed chemical analyses of K/T boundary limestone deposits from Denmark, Italy and New Zealand. Abnormally high amounts of Platinum metals (Platinum, Iridium, Osmium, and Rhodium) were found consistently in limestone samples from all locations. Alvarez and team suggest that Platinum metal amounts are consistent with the chemical structure of asteroids. The paper of further explains the details of further evidence of a asteroid impact and how an asteroid’s influence on the environment would cause mass extinction.
Should they be less/more scientific?