1. Deng, C., Du, H.: Common complements of two subspaces and an answer to Groß’s question. Acta Math. Sin. (Chinese Series) 49, 1099–1112 (2006)
2. Jin, H.: Representations of generalized inverses of the products of orthogonal projection operators and their properties (Chinese). Adv. Math. (China) 44, 809–815 (2015)
3. Lance, E.C.: Hilbert $$C^*$$-Modules-A Toolkit for Operator Algebraists. Cambridge University Press, Cambridge (1995)
4. Li, Y.: The Moore-Penrose inverses of products and differences of projections in a $$C^*$$-algebra. Linear Algebra Appl. 428, 1169–1177 (2008)
5. Li, Y.: The Moore-Penrose inverses of anti-commutators of projections in a $$C^*$$-algebra (Chinese). Acta Math. Sin. (Chin. Ser.) 52, 813–820 (2009)