Perhaps you should try some spelling variations:
nam trung » tai trung, ba trung, nam vung
nam trong » cay trong
van hanh » van thanh, ban hanh, van anh
va triet » va thiet, va trien, ve triet
so sach » so sanh, bo sach, hoc sach
co sach » bo sach, cuon sach, hoc sach
nang ma » tang ma, sang ma, nang cao
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
vi va » vi van, vai va, vu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((so sach) or (co sach)) y nang ma hoi. hieu qua ((nam trung) or (nam trong)) van hanh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (co sach)) y nang ma hoi. hieu qua ((nam trung) OR (nam trong)) van hanh vi va triet.
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (co sach)) y nang ma hoi. hieu qua ((nam trung) or (nam trong)) van hanh vi va triet*.