Buskirk ER, Komi PV.
Acta Physiol Scand. 1970 Jun;79(2):29A.
PMID: 5454901

Moore JC.
Electroencephalogr Clin Neurophysiol. 1966 Apr;20(4):405-6. doi: 10.1016/0013-4694(66)90010-1.
PMID: 4143679

Blanton PL, Biggs NL, Perkin RC.
Electromyography. 1969 May-Jul;9(2):213-4.
PMID: 5381965

Parker TG.
Am J Phys Med. 1968 Oct;47(5):247-9.
PMID: 5677809

Ekstedt J, Häggqvist P, Stålberg E.
Electroencephalogr Clin Neurophysiol. 1969 Nov;27(5):540-3. doi: 10.1016/0013-4694(69)90196-5.
PMID: 4187042