There are no known references specific to Botswana meter marks other than information that I have written, which includes:
- Botswana Meters – A Brief History, which appeared as a cover article in Forerunners, the Journal of the Philatelic Society of Greater Southern Africa in November 2001,
- Botswana Meter Marks in the Nova Scotia Stamp Club Newsletter from June 2004,
- Botswana meter marks: An introduction in the June 2022 issue of The South African Philatelist, and
- this website.
The International Postage Meter Stamp Catalog by Joel Hawkins and Richard Stambaugh (2005) contains a listing of Botswana meter marks. The authors of the catalog, while working on a revision sent a note to the author of this website stating that “due to all the new stamp types you found, we are completely redoing the Botswana pages” of the catalogue. Hawkins and Stambaugh also asked the the author of this website to examine their new pages for the catalog prior to publication. Many of the marks shown in the original catalog and on the revised pages were contributed from the collection used to create this website and the related exhibit. The International Postage Meter Stamp Catalog can now be found on-line and many of the marks in that version of the catalog are also from the collection of the exhibitor. The WikiBook directs people to this website for additional information.
Other information on meter marks in general can be found at the website of the Meter Stamp Society.