[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.