Erik Lindberg K. Murali Arünas Tamasevicius Hyperchaotic circuit with damped harmonic oscillators. 759-762 2001 conf/iscas/2001 ISCAS (3) http://doi.ieeecomputersociety.org/10.1109/ISCAS.2001.921443 db/conf/iscas/iscas2001-3.html#LindbergMT01