Willoughby, K. G. (2014). Public budgeting in context : Structure, law, reform and results. ProQuest Ebook Central. Read Chapter 4. Budget Foundations in U.S. States. This textbook chapter describes the history and rules pertaining to budgeting for the states.
Brogan, M. J. (2013). Modern budget forecasting in the american states : Precision, uncertainty, and politics. ProQuest Ebook Central. Read Chapter 4. Projecting Expenditures: Revenue Uncertainty, Public Choices, Political Institutions, Elections, and Forecast Errors. This textbook chapter elaborates on the challenges and practices of government expenditure assessment.
Kioko, S. (2017). Cost analysis. In Financial strategy for public managers (pp. 150-176). Open Textbook Library. Read Chapter 5. This textbook chapter explains the steps needed to understand the costs that a public budget must cover.
Public Budgeting in Context by 
Modern Budget Forecasting in the American States by