http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
English Grammar in use :A self-study reference and practice book for intermediate students. With answers
Raymond Murphy; Nguyễn Thị Tuyết, Đỗ Lệ Hằng, Ngọc Ánh dịch và chú giải