On Well-quasi-ordering Finite Sequences
Tài liệu tham khảo
Higman, 1952, Ordering by divisibility in abstract algebras, Proc. Lond. Math. Soc., 2, 326, 10.1112/plms/s3-2.1.326
Nash-Williams, 1963, On well-quasi-ordering finite trees, Proc. Camb. Phil. Soc., 59, 833, 10.1017/S0305004100003844