Ambler Thompson et Barry N. Taylor, -LRB- / O2008 / O-RRB-, Guide for the Use of the International System of Units -LRB- SI -RRB-, -LRB- Special publication 811 -RRB-, Gaithersburg, MD : National Institute of Standards and Technology, p. 3, footnote 2.
Unité : hertz -LRB- Hz -RRB-