There are many claims that polyphasic sleep was used by polymaths and prominent people such as Leonardo da Vinci, Napoleon, and Nikola Tesla, but there are few if any reliable sources confirming these. One first person account comes from Buckminster Fuller, who described a regimen consisting of 30-minute naps every six hours. The short article about Fuller's nap schedule in "Time" in 1943, which referred to the schedule as "intermittent sleeping", says that he maintained it for two years, and notes that "he had to quit because his schedule conflicted with that of his business associates, who insisted on sleeping like other men."