Perhaps you should try some spelling variations:
sach tham » sach nha
vat danh » va danh, van danh, luat danh
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
danh va » doanh va, hanh va, anh va
lang ha » long ha
sach ty » sach y, sach tu, sach thu
lang xa » dang xay, lang van
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua

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