Skewes and his number are discussed by Isaac Asimov in his book Of Matters Great and Small[6][7] and in the 20th edition of the Guinness Book of Records.[7][8] A memorandum written by Skewes on his retirement was kept in a glass case in the department of mathematics at the University of Cape Town. The memorandum discuses Skewes's number and further development of it.[2]