McCullough, C. B. (1937). Determination of highway system solvencies. Oregon State highway commission.
Chicago-viite (17. p.)McCullough, Conde B. Determination of Highway System Solvencies. Salem,: Oregon State highway commission, 1937.
MLA-viite (8. p.)McCullough, Conde B. Determination of Highway System Solvencies. Oregon State highway commission, 1937.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.