Searches for 117 British authors are compared in the Annual Bibliography of English Language and Literature (ABELL) and the Modern Language Association International Bibliography (MLAIB). Authors are organized by period and genre within the early modern era. The number of records for each author was subdivided by format, language of publication, and number of unique citations, defined as records retrieved in one database but not the other. Each of the unique records in one database was searched in the other to examine indexing differences. Of the unique items in ABELL, 49.1% were due to indexing differences, while indexing differences accounted for 35.4% of the unique records in MLAIB. The indexing differences significantly impacted the retrieval performance of each database. (Contains 13 tables.)