The study looks at sources of income, both legal and practical, identifies reasonable levels for library support, compares sources of governmental revenue and the costs of providing adequate library services, and develops mathematical formulas that can be used as measures of the city's or county's ability to support library services. The study also recommends uses of the formulas and applies the formulas to all counties in the state and to selected municipalities. Statistical data are presented in Table 1 and Figures 2 through 5, and two appendices contain discussions of current legislation and proposed minimum criteria for establishing public library service. Sources for the study are documented in the endnotes. (Author/KM)