A semantic definition system (a preliminary description) /

Bibliography: p. 87.

Results of spirit leveling in New York, 1906 to 1911, inclusive,

Mode of access: Internet.

Results of spirit leveling in Pennsylvania, 1899 to 1911, inclusive.

Mode of access: Internet.

Results of spirit leveling in Idaho, 1896 to 1914, inclusive,

Mode of access: Internet.

Results of spirit leveling in Iowa, 1896 to 1913, inclusive. Work done in cooperation with the State of Iowa from 1907 to 1913, inclusive.

Mode of access: Internet.

Results of spirit leveling in Nebraska, 1896 to 1913, inclusive. Work done in cooperation with the State from 1911 to 1913, inclusive, through the Board of regents of the University of Nebraska.

Mode of access: Internet.

Spirit leveling in Louisiana, 1903 to 1915, inclusive,

Mode of access: Internet.

Spirit leveling in Texas, 1896 to 1915, inclusive, work done in cooperation with the state of Texas in 1902, 1903, 1909, and 1910, and with Harris county in 1915.

Mode of access: Internet.

Traverse and leveling in Oklahoma /

"Data secured through WPA and other relief projects, sponsored by State conservation commission and Division of water resources of the Oklahoma Planning and resources board."