On a theorem of Daróczy, Lajkó and Székelyhidi
Tài liệu tham khảo
Daróczy, Z., Lajkó, K. andSzékelyhidi, L.,;Functional equations on ordered fields. Publ. Math. Debrecen.24 (1977), 173–179.
Djoković, D. Ž.,A representation theorem for (X 1−1) (X 2−1)...(X n −1)and its applications. Ann. Polon. Math.22 (1969), 189–198.