Perhaps you should try some spelling variations:
doanh va » doan va, doanh tai, doanh cua
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
sach thu » sach thue, sach thieu, sach tham
lang ha » long ha
sach ty » sach y, sach tu, xach tay
danh va » hanh va, anh va, dan va
cua tre » cua te, cuu tre, cua triet
ha hoi » hoa hoi, ha noi, xa hoi

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 ty) or (sach thu)) lang ha hoi. hieu van nam thuc vat ((danh va) or (doanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ty) OR (sach thu)) lang ha hoi. hieu van nam thuc vat ((danh va) OR (doanh va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: toc ((sach ty) or (sach thu)) lang ha hoi. hieu van nam thuc vat ((danh va) or (doanh va)) cua tre*.