Balachandran3*, G. K. S. M. and V. “Simple 4d – Hyperchaotic Canonical Van Der Pol Duffing Oscillator Using Current Feedback Op-Amp”. Recent Research in Science and Technology, vol. 3, no. 1, Dec. 2010, https://updatepublishing.com/journal/index.php/rrst/article/view/583.