“…Lacey–Thiele's breakthrough study of BHT has generated numerous investigations in multilinear operators. One direction of generalizing BHT is to replace the linear terms and with some non‐linear polynomials and , and consider the operator See the articles of Li , Li–Xiao and the first author for some recent results about . Motivated by many works on discrete linear operators (see, for example, Bourgain , Ionescu–Wainger , Krause , Mirek–Trojan , Mirek–Stein–Trojan , Pierce , Zorin–Kranich , etc.…”