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