The effect of geometry and illumination on appearance perception of different material categories
B. Chen, C. Wang, M. Piovarci, H.P. Seidel, P. Didyk, K. Myszkowski, A. Serrano, Visual Computer 37 (2021) 2975–2987.

Layer the sphere
R. Biswas, P. Bhowmick, The Visual Computer 31 (2015) 787–797.