Perhaps you should try some spelling variations:
hanh dinh » thanh dinh, hinh dinh, hanh tinh
hieu van » hieu va, thien van, lieu va
dinh cua » dinh cuu, sinh cua, dinh cu
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
van cam » van nam, van lam, van cau
truc va » thuc va, trung va
cua tre » cua te, cuu tre, cua triet
xang o » lang o, tang o, dang o
o hai » co hai, so hai, o lai

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 ty xang o hai. hieu van cam ((truc va) or (thuc vat)) hanh dinh cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty xang o hai. hieu van cam ((truc va) OR (thuc vat)) hanh dinh cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty xang o hai. hieu van cam ((truc va) or (thuc vat)) hanh dinh cua tre*.