Versions of South Dakota Codified Laws 7-18A-18. Signature requirements for referendum petition--Verification on LawServer 2023 South Dakota Codified Laws 7-18A-18. Signature requirements for referendum petition–Verification 2022 South Dakota Codified Laws 7-18A-18. Signature requirements for referendum petition–Verification 2021 South Dakota Codified Laws 7-18A-18. Signature requirements for referendum petition–Verification 2018 South Dakota Codified Laws 7-18A-18. Signature requirements for referendum petition–Verification.7-18A-18.1 2016 South Dakota Codified Laws 7-18A-18. Signature requirements for referendum petition–Verification 2014 South Dakota Codified Laws 7-18A-18. Signature requirements for referendum petition–Verification 2010 South Dakota Laws 7-18A-18 – Signature requirements for referendum petition–Verification