Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
dang xay » dang van, van xay
dinh hai » dinh thai, tinh hai, dinh ha
hieu van » thien van, lieu va, hieu ve
lang xa » lang ha, lang van
hieu va » lieu va, hieu qua
cau duc » cao duc, cau luc, chu duc
va dinh » van dinh, va kinh, va tinh
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
sach o » sach lo, sac o, sach y

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach o ((lang xa) or (dang xay)) hoi. ((hieu van) or (hieu va)) cau duc va dinh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach o ((lang xa) OR (dang xay)) hoi. ((hieu van) OR (hieu va)) cau duc va dinh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: thuoc sach o ((lang xa) or (dang xay)) hoi. ((hieu van) or (hieu va)) cau duc va dinh hai cua tre*.