Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
van nang » van quang, van ban, van dung
cua tre » cua te, cua triet, dua tren
danh di » danh du, xanh di, danh dien
va danh » va dinh, va dan, va hanh
cao luc » bao luc, cao duc, cao suc
hieu va » lieu va, hieu qua
cuu tre » cau tren, cau treo
va cao » va cac, va co, va dao
luc va » duc va, tuc va, loc va

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 ((van nang) OR (van dong)) xa hoi. hieu va cao luc va danh di ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((van nang) OR (van dong)) xa hoi. hieu va cao luc va danh di ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((van nang) OR (van dong)) xa hoi. hieu va cao luc va danh di ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((van nang) OR (van dong)) xa hoi. hieu va cao luc va danh di ((cua tre) or (cuu tre))*.