Perhaps you should try some spelling variations:
sach pham » sach tham, sach phat, sach phap
hieu van » hieu va, thien van, lieu va
thang va » hang va, thong va, thanh va
trang va » tran van, hang va
dau thuc » dan thuc, dai thuc, dam thuc
danh vi » dinh vi, danh di, danh va
tu sach » thu sach, su sach, te sach
van dau » van dao, phan dau
cuu tre » cua tre, cau tren, cau treo

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 pham ((thang va) or (trang va)) hoi. hieu van dau thuc vat ((danh vi) or (hanh vi)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach pham ((thang va) OR (trang va)) hoi. hieu van dau thuc vat ((danh vi) OR (hanh vi)) cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach pham ((thang va) or (trang va)) hoi. hieu van dau thuc vat ((danh vi) or (hanh vi)) cuu tre*.