Constructing hyperchaotic attractors of conditional symmetry Zhenyu Gu, Chunbiao Li, Herbert H.C. Iu, Fuhong Min and Yibo Zhao Eur. Phys. J. B, 92 10 (2019) 221 Published online: 02 October 2019 DOI: 10.1140/epjb/e2019-100165-9