National Conference of State Legislatures (NCSL) Federation of Tax Administrators (FTA) North Eastern States Tax Officials Association (NESTOA) Southeastern Association of Tax Administrators (SEATA) Western States Association of Tax Administrators (WSATA) Midwest States Association of Tax Administrators (MSATA) Streamlined Sales Tax Project (SSTP) Multistate Tax Commission (MTC) Database of State Incentives for Renewables & Efficiency State Government Affairs Council (SGAC) State Legislatures State Tax Agencies Tax Foundation TAXSites.com Mobile Workforce Coalition National Governors Association (NGA) Multistate Associates