* David J. Breeze, "A Note on the Use of the Titles 'Optio' and 'Magister' below the Centurionate during the Principate", ''Britannia'' 7, 1976, pp. 127-133[http://www.jstor.org/pss/525768]. | * David J. Breeze, "A Note on the Use of the Titles 'Optio' and 'Magister' below the Centurionate during the Principate", ''Britannia'' 7, 1976, pp. 127-133[http://www.jstor.org/pss/525768]. |