1. Michael Tait, My favorite application using eigenvalues: Eigenvalues and the Graham–Pollak theorem, https://mathweb.ucsd.edu/-fan/teach/262/13/262notes/Tait_Eigenvalue_Essay.pdf, Winter 2013.
2. Suhail Sherif, A theorem with only rude proofs: The Graham–Pollak theorem, https://www.youtube.com/watch?v=6ByCnuCbPsg&t=3s, Aug 2021.
3. R. L. Graham and H. O. Pollak, On the addressing problem for loop switching, Bell System Tech. J., Vol.50, pp.2495–2519, 1971.
4. R. L. Graham and H. O. Pollak, On embedding graphs in squashed cubes, In Graph theory and applications (Proc. Conf., Western Michigan Univ., Kalamazoo, Mich., 1972
5. (dedicated to the memory of J. W. T. Youngs), Vol.303 of Lecture Notes in Math, pp.99-110. Springer, Berlin, 1972.