@article{20198,
      recid = {20198},
      title = {Training course on patent documentation and searching :  Sofia, Bulgaria October 22 to November 2, 1990.},
      pages = {1 volume (various paging) ;},
      note = {organized by the World Intellectual Property Organization  (WIPO) in cooperation with the Institute of Inventions and  Rationalization of Bulgaria and with the assistance of the  United Nations Development Programme (UNDP); Contents :  WIPO. General introduction to the use of patent documents  and the technological information contained therein; WIPO.  The International Patent Classification (IPC), its  philosophy and use; International cooperation in the field  of patent information and the role of WIPO;.},
      url = {http://tind.wipo.int/record/20198},
      doi = {https://doi.org/10.34667/tind.20198},
}