about the cited book Cook: are you sure you do not want to use:
 { {citebook|title=The Encyclopedia of the Chemical Elements|pages=499-511|isbn=0278916430|author=Clifford A. Hampel|year=1968|publisher=Thomson Learning (EMEA) Ltd} }
 instaed of:   Cook, Gerhard A.; Lauer, Carol M. (1968). "Oxygen", in Clifford A. Hampel: The Encyclopedia of the Chemical Elements. New York: Reinhold Book Corporation, 499-512. LCCN 68-29938