"Half-high dots or spaces are used to express a derived unit formed from two or more other units by multiplication."
Barry N. Taylor. (2001 ed.) The International System of Units.Արխիվացված 2016-06-03 Wayback Machine
(Special publication 330). Gaithersburg, MD: National
Institute of Standards and Technology. 20.
web.archive.org
"Half-high dots or spaces are used to express a derived unit formed from two or more other units by multiplication."
Barry N. Taylor. (2001 ed.) The International System of Units.Արխիվացված 2016-06-03 Wayback Machine
(Special publication 330). Gaithersburg, MD: National
Institute of Standards and Technology. 20.