David Chaum, Richard Carback, Jeremy Clark, Alexander Essex, Stefan Popoveniuc, Ronald L. Rivest, Peter Y. A. Ryan, Emily Shen, Alan T. Sherman: Scantegrity II: End-to-End Verifiability for Optical Scan Election Systems using Invisible Ink Confirmation Codes. Proceedings of USENIX/ACCURATE EVT, 2008. Artikkelin verkkoversio.