Perhaps you should try some spelling variations:
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
danh vai » danh sai, danh va, doanh van
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
van cau » van dau, van hau, van chat
truc va » thuc va, thuc vat, trung va
va danh » va dinh, va dan, va hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet

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 y ((nang xa) or (dang xay)) hoi. hieu van cau truc va danh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (dang xay)) hoi. hieu van cau truc va danh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) or (dang xay)) hoi. hieu van cau truc va danh vai cua tre*.