Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
chat xu » chat xuc, chao xu, chat huu
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
ve chat » va chat, van chat
xu van » tu van, vu van, su van
va va » va van, va vai, va vat

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 y ((nang xa) or (nang ma)) hoi. hieu ve chat xu van hanh ((va va) or (va vua)) thieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang xa) OR (nang ma)) hoi. hieu ve chat xu van hanh ((va va) OR (va vua)) thieu.
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang xa) or (nang ma)) hoi. hieu ve chat xu van hanh ((va va) or (va vua)) thieu*.