Report on the birds of Pennsylvania; with special reference to the food habits, based on over four thousand stomach examinations - Pennsylvania. Ornithologist. (E.K. Meyers, State Printer, 1890)

Report on the ornithology of the Death Valley Expedition of 1891 - United States. Bureau of Biological Survey. (U.S. G.P.O.?], 1893)

Report on the progress and condition of the U.S. National Museum for the year ending June 30 ... - United States National Museum (G.P.O, 1914)

Report upon natural history collections made in Alaska : between the years 1877 and 1881 - Bean, Tarleton H. (Tarleton Hoffman), 1846 -1916 (Government Printing Office, 1887)

Report upon natural history collections made in Alaska between the years 1877 and 1881 - Bean, Tarleton H. (Tarleton Hoffman), 1846 -1916 (Govt. Print. Off, 1887)

Report upon ornithological specimens collected in the years 1871, 1872, and 1873 - Geographical Surveys West of the 100th Meridian (U.S.) (Govt. Print. Off, 1874)

Report upon United States Geographical surveys west of the one hundredth meridian - Geographical Surveys West of the 100th Meridian (U.S.) (G.P.O, 1875)

Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean - Baird, Spencer Fullerton, 1823 -1887 (A.O.P. Nicholson, Printer [etc.], 1858)

Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean - Baird, Spencer Fullerton, 1823 -1887 (A.O.P. Nicholson, Printer [etc.], 1853)

Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean - Baird, Spencer Fullerton, 1823 -1887 (A.O.P. Nicholson, Printer [etc.], 1859)

Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean - Baird, Spencer Fullerton, 1823 -1887 (A.O.P. Nicholson, Printer [etc.], 1860)

A reprint of the North American zoology, by George Ord. Being an exact reproduction of the part originally compiled by Mr. Ord for Johnson & Warner, and first published by them in their 2d American ed. of Guthrie's geography, in 1815. Taken - Ord, George, 1781 -1866 (Pub. by the editor, 1894)

Research needs for forest and rangeland management in Arizona and New Mexico - Rocky Mountain Forest; Range Experiment Station (Fort Collins, Colo.) (Rocky Mountain Forest and Range Experiment Station, 1997)

Resource management report - Ontario. Fish; Wildlife Branch.

Results of a biological reconnoissance of south-central Idaho - Stejneger, Leonhard, 1851 -1943 (Govt. Print. Off, 1891)

Results of a biological reconnoissance of the Yukon river region. : General account of the region. Annotated list of mammals - Osgood, Wilfred Hudson, 1875 -1947 (Government Printing Office, 1900)

Results of a biological survey of Mount Shasta, California - Merriam, C. Hart (Clinton Hart), 1855 -1942 (Govt Print. Off, 1899)

Results of a biological survey of the San Francisco Mountain region and desert of the Little Colorado, Arizona - Stejneger, Leonhard, 1851 -1943 (Govt. Print. Off, 1890)

Results of a biological reconnoisance of the Yukon river region. General account of the region. Annotated list of mammals - Osgood, Wilfred Hudson, 1875 -1947 (Govt. Print. Off, 1900)

Results of a biological reconnoissance of the Yukon River region - Osgood, Wilfred Hudson, 1875 -1947 (G.P.O, 1900)

Returns from banded birds, 1920 to 1923 - United States. Department of Agriculture. (U.S. Dept. of Agriculture, 1924)

A review of the birds of Connecticut - Merriam, C. Hart (Clinton Hart), 1855 -1942 (Tuttle, Morehouse & Taylor, Printers, 1877)

A review of the ornithology of Minnesota - Roberts, Thomas S. (Thomas Sadler), 1858 -1946 (1919)

A revised catalogue of the birds of Kansas : with descriptive notes of the nests and eggs of the birds known to breed in the state - Goss, N. S. (Nathaniel S.) (Kansas Publishing House, 1886)

A revised catalogue of the birds of Kansas. With descriptive notes of the nests and eggs of the birds known to breed in the state - Goss, N. S. (Nathaniel S.) (Kansas Publishing House, 1886)

A revised list of Cincinnati birds - Langdon, Frank Warren, 1852 -1933 (Barclay, 1879)

The riddle of migration - Rowan, William, 1891 -1957 (Williams & Wilkins Company, 1931)

Riverby - Burroughs, John, 1837 -1921 (Houghton, Mifflin, 1895)

Riverby - Burroughs, John, 1837 -1921 (Houghton, Mifflin, 1902)

Rivista italiana di ornitologia - Museo civico di storia naturale di Milano. (Società italiana di scienze naturali, 1913)

Rivista italiana di ornitologia - Museo civico di storia naturale di Milano. (Società italiana di scienze naturali, 1918)

Roosevelt wild life annals - New York State College of Forestry at Syracuse University. Roosevelt Wild Life Forest Experiment Station. (Roosevelt Wild Life Forest Experiment Station, 1932)

Roosevelt wild life bulletin ... of the Roosevelt Life Forest Experiment Station of the New York College of Forestry at Syracuse University - New York State College of Forestry at Syracuse University. Roosevelt Wild Life Forest Experiment Station. (The University, 1921)