Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
van hanh » van thanh, ban hanh, van anh
va trien » va truyen, va thiet, va tuyen
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » hieu qua
cam luc » cam xuc, cau luc
luc van » luoc van, luu van, duc van
hanh di » hanh vi, hanh de, hang di
sach v » sach va, sach 2, sach vay
di va » dai va, di vao, doi 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 y)) sang mai hoi. ((hieu va) or (lieu va)) cam luc van hanh di va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach v) OR (sach y)) sang mai hoi. ((hieu va) OR (lieu va)) cam luc van hanh di va trien.
• Adding a wildcard symbol may retrieve word variants: toc ((sach v) or (sach y)) sang mai hoi. ((hieu va) or (lieu va)) cam luc van hanh di va trien*.