books.google.co.ukhttp://books.google.co.uk/books/about/M_Tullii_Ciceronis_Cato_major_sive_de_se.html?id=oIgCAAAAQAAJ&utm_source=gb-gplus-shareM. Tullii Ciceronis Cato major sive de senectute, Lælius sive de amicitia, et epistolæ selectæ. Recens. G. Long
