[337] De Bello Gallico, VI. 13.
[338] Agricola, 11.
[339] Strabo, IV., p. 199.
[340] De Bello Gallico, V. 12.
[341] Diodorus Siculus, V. 22.
[342] Pliny, Hist. Nat., IV. 30, § 16.
[343] Tacitus, Agricola, 36.
[344] De Bello Gallico, V. 16.
[345] Tacitus, Agricola, 12.
[346] Frontinus, Stratagm., II. 3, 18.—Diodorus Siculus, V. 21.—Strabo, IV., p. 200.