Tutorial: Coarse-graining of Spin Foams

          @misc{ scivideos_PIRSA:17060087,
            doi = {10.48660/17060087},
            url = {https://pirsa.org/17060087},
            author = {Bahr, Benjamin and Dittrich, Bianca and Steinhaus, Sebastian},
            keywords = {Quantum Gravity},
            language = {en},
            title = {Tutorial: Coarse-graining of Spin Foams},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2017},
            month = {jun},
            note = {PIRSA:17060087 see, \url{https://scivideos.org/pirsa/17060087}}
          }