1. Adamchik, V., Wagon, S.: $$\pi $$: A 2000-year-old search changes direction. Math. Edu. Res. 5, 11–19 (1996)
2. Adamchik, V., Wagon, S.: A simple formula for $$\pi $$. Am. Math. Mon. 104, 852–855 (1997)
3. Adegoke, K., Lafont, J.O., Layeni, O.: A class of digit extraction BBP-type formulas in general binary bases. Notes Number Theory Discret. Math. 17, 18–32 (2011)
4. Bailey, D.H.: The BBP algorithm for pi.
http://www.davidhbailey.com/dhbpapers/bbp-alg.pdf
(2006),
5. Bailey, D.H.: A compendium of BBP-type formulas for mathematical constants.
http://www.davidhbailey.com/dhbpapers/bbp-formulas.pdf
(2017)