Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
cam thuc » am thuc, nam thuc, cam thu
so sach » so sanh, bo sach, co sach
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
van cam » van nam, van lam, van cau
sach ly » sach y, sach lo, sach ty
hang ca » hang va, nang cao, hang tai
hang xa » hoang xa, hang va, lang xa
cuu 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: so sach ly ((hang xa) OR (hang ca)) hoi. hieu van cam thuc va hanh tai ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ly ((hang xa) OR (hang ca)) hoi. hieu van cam thuc va hanh tai ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ly ((hang xa) OR (hang ca)) hoi. hieu van cam thuc va hanh tai ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: so sach ly ((hang xa) OR (hang ca)) hoi. hieu van cam thuc va hanh tai ((cua tre) or (cuu tre))*.