I. Runkel and L. Szegedy, “Area-dependent quantum field theory,” Communications in Mathematical Physics, vol. 381, no. 1. Springer Nature, pp. 83–117, 2021.

N. Kalinin and M. Shkolnikov, “Sandpile solitons via smoothing of superharmonic functions,” Communications in Mathematical Physics, vol. 378, no. 9. Springer Nature, pp. 1649–1675, 2020.