Why a historian may omit a seminal work

Why would a historian omit a seminal work on the subject from the source list?

The work may not have been cited when primary sources carried the argument and space was limited, or the author may wish to avoid turning a difference of interpretation into an artificial controversy.

Two reasons can explain why an important book does not appear in a historian's source list. A bibliography and recommended-reading list cannot include every relevant secondary work because books still face word and page limits. If a section rests directly on primary sources and does not cite a particular secondary work, even an excellent book may be left out. The other reason arises when a famous study and a new book interpret the same evidence differently. A marketing team could present that difference as a dramatic claim that the new book disproves the old one. Some historians welcome that controversy, while others prefer to let a book stand on its own evidence and argument. Returning to the primary sources can keep a difference of analytical perspective from becoming a manufactured feud.