The reverse order laws for {1,
xA0;3,
xA0;4}-generalized inverses of a product of two operators have been studied by Wang et al. [J. Wang, H. Zhang, G. Ji, A generalized reverse order law for the products of two operators, Journal of Shaan
xi Normal University, 38 (4) (2010), 13-17].
In this paper using a block-operator matrix technique we study mixed-type reverse-order laws for {1,xA0;3,xA0;4}-generalized inverses over Hilbert spaces.