Publications
A Geographical Bibliography of British Ornithology from the earliest times to the end of 1918, arranged under counties, by William Herbert Mullens, published 1920 (London: Witherby & Co.) View Online
William Markwick. A biographical sketch and notes on his natural history manuscripts now in the Hastings Museum, by William Herbert Mullens, published 1922 in Hastings and East Sussex Naturalist (vol. 3, no. 5, article, pp.179-198)
Notes on Sussex Ornithology, being extracts from the Diaries of Robert Nathaniel Dennis, rector of East Blatchington, by William Herbert Mullens and N. F. Ticehurst, published 1925 (London: H. F. & G. Witherby) accessible at: & West Sussex Libraries & East Sussex Libraries
A Short History of Bexhill in the County of Sussex, by William Herbert Mullens, published 1927 (30 pp., published by the author) accessible at: W.S.R.O. [Lib 10236][Lib 13875] & The Keep [LIB/503757] & East Sussex Libraries