A "skew chain order" is one which can be partitioned into saturated chains all starting at rank 0. A two-part Sperner-type theorem is derived for the direct product of two skew chain orders. This theorem is used to solve an extremal problem about certain sets of integer rectangles. © 1979.
West, D. B., & Kleitman, D. J. (1979). Skew chain orders and sets of rectangles. Discrete Mathematics, 27(1), 99–102. https://doi.org/10.1016/0012-365X(79)90073-6