RT Journal Article SR Electronic T1 Contributions from the Sheffield Laboratory of Yale College on the equivalent and spectrum of caesium JF American Journal of Science JO Am J Sci FD American Journal of Science SP 94 OP 98 DO 10.2475/ajs.s2-35.103.94 VO s2-35 IS 103 A1 Johnson, S. W. A1 Allen, O. D. YR 1863 UL http://www.ajsonline.org/content/s2-35/103/94.abstract AB