Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
ban tinh » ban thanh, quan tinh, ban hanh
pham cuc » pham chuc, pham duc, pham cua
van pham » san pham, van phan, van phat
tinh va » tich va, trinh van, trinh vat
cuc ban » cua ban, cac ban, cuu ban
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
dang ha » dong ha, dung ha, lang ha
dang xa » dang xay, lang xa, dang va
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: tu sach ky ((dang xa) or (dang ha)) hoi. hieu van pham cuc ban tinh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((dang xa) OR (dang ha)) hoi. hieu van pham cuc ban tinh va cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((dang xa) or (dang ha)) hoi. hieu van pham cuc ban tinh va cua tre*.