How many ways can two composition series intersect? - Gábor Czédli; László Ozsvárt; Balázs Udvari (Discret. Math., 2012)

Minimum Number of Monotone Subsequences of Length 4 in Permutations. - József Balogh; Ping Hu 004; Bernard Lidický; Oleg Pikhurko; Balázs Udvari; Jan Volec (Comb. Probab. Comput., 2015)