See the literature cited above, and in addition note the following: Fritzsche, Exegetisches Handbuch zu den Apokryphen (1851), 67-108; Schurer, History of the Jewish People, II, iii, 181 ff (Ger. edition 4, III, 449 ff); Ryssel (in Kautzsch, Apocrypha, 193 ff); Swete, Introduction to the Old Testament in Greek, 257 if; the articles in the principal Bible Dictionaries, including Jewish Encyclopedia and Encyclopedia Britannica (11th edition).