NodMutDB: a database for genes and mutants involved in symbiosis. - Chunhong Mao; Jing Qiu; Chunxia Wang; Trevor C. Charles; Bruno W. S. Sobral (Bioinform., 2005)

MetaProx: the database of metagenomic proximons. - Gregory Vey; Trevor C. Charles (Database J. Biol. Databases Curation, 2014)