McWhirter, Ross; McWhirter, Norris (29 September 1972). "Guinness Book of World Records". Sterling Publishing Company. Archived from the original on 9 January 2021. Retrieved 27 August 2017.
McWhirter, Ross; McWhirter, Norris (29 September 1972). "Guinness Book of World Records". Sterling Publishing Company. Archived from the original on 9 January 2021. Retrieved 27 August 2017.