Perhaps you should try some spelling variations:
dai nguoi » dao nguoi, doi nguoi, dau nguoi
thuc dai » thuc day, thuc tai, thu dai
thuc dan » thuc hanh, hoc dan, thuc vat
te cach » ve cach, te sach, tu cach
su cach » tu cach, su cac, cuu cach
su sach » so sach, vu sach
hoc dai » hoc dan

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

• If you are trying to use Boolean operators, they must be ALL CAPS: "((\"te cach ((thuc dai) OR (thuc dan)) nguoi\") or (\"((su cach) OR (su sach)) hoc dai nguoi\"))".
• The words AND, OR and NOT may confuse the search; try adding quotes: "\"((\\"te cach ((thuc dai) OR (thuc dan)) nguoi\\") or (\\"((su cach) or (su sach)) hoc dai nguoi\\"))\"".
• Removing quotes may allow a broader search: (( te cach ((thuc dai) OR (thuc dan)) nguoi ) or ( ((su cach) or (su sach)) hoc dai nguoi )).