Bacillus-fag phi29 (Φ29 fag) pripada porodici srodnih bakteriofaga, koji, pored Φ29, uključuju fage PZA, Φ15, BS32, B103, M2Y (M2), Nf i GA-1.[1][2] Ovi fagi, koji čine dio porodice Podoviridae, najmanji su Bacillus-fagi izolirani i među najmanjima do sada poznatim dsDNK- fagima.[3]
^Mc Grath S and van Sinderen D (editors). (2007). Bacteriophage: Genetics and Molecular Biology (1st izd.). Caister Academic Press. ISBN978-1-904455-14-1.
^CAMACHO, Ana; JIMENEZ, Fernando; TORRE, Javier; CARRASCOSA, Jose L.; MELLADO, Rafael P.; VINUELA, Eladio; SALAS, Margarita; VASQUEZ, Cesar (februar 1977). "Assembly of Bacillus subtilis Phage Phi29. 1. Mutants in the Cistrons Coding for the Structural Proteins". European Journal of Biochemistry. 73 (1): 39–55. doi:10.1111/j.1432-1033.1977.tb11290.x.