Maude's is probably the most authoritative work on the 1806 Campaign published in the English language. Obviously, it does not go into the subject matter in the same depth as the French and German General Staffs, but Maude drew extensively on this material and made it available to the monolingual reader.
His account is largely balanced and Maude shows a deep understanding of the issues surrounding this campaign.
Muade is certainly more authoritative than his contemporary Petre and the quality of his work has yet to be surpassed by anybody writing in the English language.
The Jena Campaign 1806
1988 Greenhill Books - facsimilie of 1909 edition
Napoleonic Library #33