@misc{2018-PATENT-PiezoelectricFilmStructure,
   author = {Wang, Xing and Zhang, Biyong and Hu, Jun},
   title = {Piezoelectric Film Structure},
   number = {201720601896 .8},
   ISBN = {ZL 2017 20 601896.8},
   PDF = {http://www.drhu.eu/publications/2018-PATENT-PiezoelectricFilmStructure.pdf},
   year = {2018}
}