1. Instance-based learning algorithms;Aha;Mach. Learn.,1991
2. C. Alexandru, D. van Donselaar, F. Tobin, S. Renkema, T. Meyer, Pyzor 1.0 Documentation, https://pyzor.readthedocs.io/en/release-1-0-0/, 2014 (accessed November 7, 2016).
3. DomainKeys Identified Mail (DKIM) Signatures;Allman,2007
4. A study of spam filtering using support vector machines;Amayri;Artif. Intell. Rev.,2010
5. The Apache SpamAssassin project - The #1 Enterprise Open-Source Spam Filter, 2017,2007