RT Journal Article SR Electronic T1 On the occurrence of xenotime as an accessory element in rocks JF American Journal of Science JO Am J Sci FD American Journal of Science SP 308 OP 311 DO 10.2475/ajs.s3-41.244.308 VO s3-41 IS 244 A1 Orville Adelbert Derby YR 1891 UL http://www.ajsonline.org/content/s3-41/244/308.abstract AB