http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Stephen Slater [và nh.ng. khác] ch.b, ; Nguyễn Thành Yến chú giải
IELTS (Trắc nghiệm tiếng Anh giao tiếp quốc tế)
Sách giáo khoa cho người nước ngoài