RT Journal Article SR Electronic T1 Types of orographic structure JF American Journal of Science JO Am J Sci FD American Journal of Science SP 414 OP 428 DO 10.2475/ajs.s3-12.72.414 VO s3-12 IS 72 A1 John Wesley Powell YR 1876 UL http://www.ajsonline.org/content/s3-12/72/414.abstract AB