1. ProofPeer. http://www.proofpeer.net
2. Obua, S., Fleuriot, J., Scott, P., Aspinall, D.: ProofPeer: Collaborative Theorem Proving. arXiv: 1404.6186 (2013)
3. ProofScript. http://proofpeer.net/topics/proofscript
4. Obua, S., Scott, P., Fleuriot, J.: Local Lexing. http://proofpeer.net/papers/locallexing
5. Scott, P., Obua, S., Fleuriot, J.: Bootstrapping LCF Declarative Proofs. http://proofpeer.net/papers/bootstrapping