Perhaps you should try some spelling variations:
hanh dinh » thanh dinh, hinh dinh, hanh tinh
dinh cuu » dinh chi
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
truc va » thuc va, trung va
van cam » van nam, van lam, van cau
sach ty » sach y, sach tu, sach thu
cuu tre » cua tre, cau tren, cau treo
tang o » trang o, lang o
xang o » lang o, dang o

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) OR (tang o)) hai. hieu van cam ((truc va) or (thuc vat)) hanh dinh cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((xang o) OR (tang o)) hai. hieu van cam ((truc va) OR (thuc vat)) hanh dinh cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((xang o) OR (tang o)) hai. hieu van cam ((truc va) or (thuc vat)) hanh dinh cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((xang o) OR (tang o)) hai. hieu van cam ((truc va) or (thuc vat)) hanh dinh cuu tre*.