Perhaps you should try some spelling variations:
"so mach hoc giao nguoi" » "so mach hoc gian nguoi", "so mach hoc giap nguoi", "so mach hoc giau nguoi", "so cach hoc giao nguoi", "so dich hoc giao nguoi", "so anh hoc giao nguoi", "so mach hoc cao nguoi", "so sach hoc giao nguoi", "tao mach hoc giao nguoi", "kon mach hoc giao nguoi"
"thu sach hoc tap nguoi" » "thu sach hoc tay nguoi", "thu sach hoc gap nguoi", "thu sach hoc tac nguoi", "tu sach hoc tap nguoi", "thuat sach hoc tap nguoi", "thuoc sach hoc tap nguoi", "thu cach hoc tap nguoi", "thu sach hoi tap nguoi", "thu sach duoc tap nguoi"
"ngoi lich hoc dao nguoi" » "ngoc bich hoc dao nguoi", "ngoi lich hoc cho nguoi", "ngoi dich hoc dao nguoi", "ngoi lich thuc dao nguoi", "ngoi sinh hoc dao nguoi", "ngoi lich hoc dan nguoi", "ngoi lich hoc cao nguoi", "ngoi lich hoc dai nguoi"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("thu sach hoc tap nguoi") or ((("ngoi lich hoc dao nguoi") or ("so mach hoc giao nguoi"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("thu sach hoc tap nguoi") OR ((("ngoi lich hoc dao nguoi") OR ("so mach hoc giao nguoi")))).
• Removing quotes may allow a broader search: (( thu sach hoc tap nguoi ) or ((( ngoi lich hoc dao nguoi ) or ( so mach hoc giao nguoi )))).
• Adding a wildcard symbol may retrieve word variants: (("thu sach hoc tap nguoi") or ((("ngoi lich hoc dao nguoi") or ("so mach hoc giao nguoi"))))*.