Наш језик (том 3 изд.). Лингвистичко друштво. 1952. стр. 166. Приступљено 3. 9. 2017.
Вукићевић, Даница; Ћирковић, Симо (2006). Српска породична енциклопедија (Том 9 изд.). Народна књига. Приступљено 3. 9. 2017.
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physics.nist.gov
„Guide for the Use of the International System of Units (SI)”(PDF). physics.nist.gov. National Institute of Standards and Technology. 2008. Архивирано(PDF) из оригинала 3. 6. 2016. г. Приступљено 25. 1. 2017. „Reference [4: ISO 31-0] suggests that if a space is used to indicate units formed by multiplication, the space may be omitted if it does not cause confusion. This possibility is reflected in the common practice of using the symbol kWh rather than kW ⋅ h or kW h for the kilowatt hour. Nevertheless, this Guide takes the position that a half-high dot or a space should always be used to avoid possible confusion;”
„Guide for the Use of the International System of Units (SI)”(PDF). physics.nist.gov. National Institute of Standards and Technology. 2008. Архивирано(PDF) из оригинала 3. 6. 2016. г. Приступљено 25. 1. 2017. „Reference [4: ISO 31-0] suggests that if a space is used to indicate units formed by multiplication, the space may be omitted if it does not cause confusion. This possibility is reflected in the common practice of using the symbol kWh rather than kW ⋅ h or kW h for the kilowatt hour. Nevertheless, this Guide takes the position that a half-high dot or a space should always be used to avoid possible confusion;”