Francisco Bulnes,  Topological Quantum Diffeomorphisms in Field Theory and the Spectrum of the Space-Time .   journal   = {International Journal of Physical and Mathematical Sciences}, [online]. World Academy of Science, Engineering and Technology.
    March 2017, vol. 125(5). 192 - 195
    [viewed 19 April 2024]. Available from: https://publications.waset.org/pdf/10006924.