1.1. In English Dictionaries and Encyclopedias

• Bishop | New International Dictionary of New Testament Theology
• Elder in the NT | The International Standard Bible Encyclopedia, Revised

1.2. In Bible Dictionaries and Encyclopedias

1.3. In Theological Dictionaries and Encyclopedias

• Elders | Concise Theology
• Elder | Evangelical Dictionary of Biblical Theology

1.4. In Theological Journals

2.1. In Systematic Theologies

2.2. In Other Books

• Contents | The Elders: Seniority within Earliest Christianity