Advanced General Relativity - Lecture 4

          @misc{ scivideos_PIRSA:13010015,
            doi = {},
            url = {https://pirsa.org/13010015},
            author = {Sorkin, Rafael},
            keywords = {},
            language = {en},
            title = {Advanced General Relativity - Lecture 4},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2013},
            month = {jan},
            note = {PIRSA:13010015 see, \url{https://scivideos.org/pirsa/13010015}}
          }