Perhaps you should try some spelling variations:
tang dai » tang tai, tang dan, lang dai
dam thuc » am thuc, dan thuc, nam thuc
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
hieu ve » hieu va, hieu van
ca viet » va viet, co viet, san viet
cam tu » cam thu, nam tu, dam tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky tang dai hoc. hieu ve ((dam thuc) or (cam tu)) van hanh vi ((ca viet) or (hoa viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky tang dai hoc. hieu ve ((dam thuc) OR (cam tu)) van hanh vi ((ca viet) OR (hoa viet)).
• Adding a wildcard symbol may retrieve word variants: su sach ky tang dai hoc. hieu ve ((dam thuc) or (cam tu)) van hanh vi ((ca viet) or (hoa viet))*.