Enoka & Pearson (2013), Table 34-1 Innervation Numbers in Human Skeletal Muscles, p. 770 harvp error: no target: CITEREFEnokaPearson2013 (help) อ้างอิง Enoka, RM (2008). "Chapter 6: Muscle and motor units". Neuromechanics of Human Movement. Champaign, IL: Human Kinetics. pp. 218.
Karpati, George (2010). Disorders of Voluntary Muscle(PDF). Cambridge University Press. p. 7. ISBN9780521876292. อ้างอิง Feinstein, B; Lindegard, B; Nyman, E; Wohlfart, G (1955). "Morphologic studies of motor units in normal human muscles". Acta Anat (Basel). 23 (2): 127–142.