Perhaps you should try some spelling variations:
thien van » thi van
nang cau » nang cao, hang cau, nang dau
van cham » van chat, van tham, va cham
van hanh » van thanh, ban hanh, van anh
hanh lai » hanh lam, hanh tai, thanh lap
sach ty » sach tu, sach thu, xach tay
soc van » hoc van, oc van, sac van
su viet » so viet

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ty) or (sach y)) nang cau hoi. thien van cham soc van hanh lai su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach y)) nang cau hoi. thien van cham soc van hanh lai su viet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach y)) nang cau hoi. thien van cham soc van hanh lai su viet*.