Bruel & Kjaer - 4269
Documentation
https://www.nuigalway.ie/media/publicsub-sites/engineering/files/B&K_4344_8307.pdf
https://www.bksv.com/media/doc/bn1329.pdf
Applications
https://www.scribd.com/document/360000052/pub13-pdf
http://nros415.webhost.uits.arizona.edu/hlab/readings/Sarcophaga%20CNS.pdf
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.472.8917&rep=rep1&type=pdf
