Many reference works have been rendered obsolete by advances in archaeology, textual criticism, palaeography, and other related disciplines.
All Bible dictionaries, Bible encyclopaedias, and commentaries published before 1965 are out of date.
Exercise caution when using them, and cross-check against more recent publications.
Beware of modern reprints, such as this 'concise edition' of Robertson's Word Pictures in the New Testament (first published in 1930 and now in public domain). They offer no improvements to the original work, and should be avoided.