http://www.iltax.com/Businesses/TaxInformation/Sales/rot.htm
http://www.ilga.gov/legislation/ilcs/ilcs.asp
www.revenue.state.il.us/LegalInformation/regs/index.htm/
http://www.state.il.us/court/Opinions/default.htm
http://business.illinois.gov/tax_forms.cfm
email – mbrandenburg@revenue.state.il.us
Tel. – 1-800-732-8866 or (217) 782-3336
Mail – Illinois State Sales Tax, Illinois Department of Revenue, P.O. Box 19041, Springfield, IL 62794-9041