Napier, John (1889). The Construction of the Wonderful Canon of Logarithms. Превод: Macdonald, William Rae. Edinburgh: Blackwood & Sons — преко Internet Archive. „In numbers distinguished thus by a period in their midst, whatever is written after the period is a fraction, the denominator of which is unity with as many cyphers after it as there are figures after the period.”
wolfram.com
mathworld.wolfram.com
Weisstein, Eric W. (10. 3. 2022). „Decimal Point”. Wolfram MathWorld (на језику: енглески). Приступљено 17. 3. 2022.CS1 одржавање: Формат датума (веза)