Dynamical and fractal properties in periodically forced stretch-twist-fold (STF) flow Muhammad Aqeel, Salman Ahmad, Anam Azam and Faizan Ahmed Eur. Phys. J. Plus, 132 5 (2017) 219 Published online: 18 May 2017 DOI: 10.1140/epjp/i2017-11487-7