Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
sach va » sach xa, sach ha, sach dao
nang ma » tang ma, sang ma, nang cao
hieu va » hieu qua
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
ma hoi » mai hoi, xa hoi, ma hoa
sach v » sach y, sach 2, sach vay
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: toc ((sach v) or (sach va)) nang ma hoi. ((hieu va) or (lieu va)) cam duc va hanh vi va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach v) OR (sach va)) nang ma hoi. ((hieu va) OR (lieu va)) cam duc va hanh vi va trien.
• Adding a wildcard symbol may retrieve word variants: toc ((sach v) or (sach va)) nang ma hoi. ((hieu va) or (lieu va)) cam duc va hanh vi va trien*.