“Hilbert-Schmidtness of Submodules in $H^2 (\mathbb{D}^2 )$ Containing $θ(z)−\varphi (w)$”. Communications in Mathematical Research, vol. 39, no. 3, Apr. 2023, pp. 331-4, https://doi.org/10.4208/cmr.2022-0034.