Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
tu xang » ty xang, tu lang, tu quang
va hanh » va thanh, va danh, ban hanh
xang x » nang x
va cam » va cham, va cao, va cai
x hoi » xa hoi, o hoi, x ho
vi va » vi van, vai va, vu va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach tu xang x hoi. hieu ((va cac) or (va cam)) tuc ((va hanh) or (van hanh)) vi va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu xang x hoi. hieu ((va cac) OR (va cam)) tuc ((va hanh) OR (van hanh)) vi va thiet.
• Adding a wildcard symbol may retrieve word variants: su sach tu xang x hoi. hieu ((va cac) or (va cam)) tuc ((va hanh) or (van hanh)) vi va thiet*.