Strong Versions of Sperner’s Theorem
Journal of Combinatorial Theory, Series A
A procedure for partitioning the collection of divisors of an integer into symmetric chains is described and analyzed in detail. As a consequence, several strengthenings of Sperner's theorem are obtained. The algorithm also leads to elementary combinatorial proofs of a number of results on lattice paths and plane partitions.
Greene, C. and D. J. Kleitman. “Strong versions of Sperner’s theorem”, Journal of Combinatorial Theory 20 (1976), 80-88.