Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hanh hai » thanh hai, nhanh hai, hang hai
hai cua » thai cua, dai cua, hoi cua
hieu va » lieu va, hieu qua
le dang » le tang, le dan, le quang
le lang » le tang, le xang, le bang
va cam » va cham, va cac, va cao
luc va » tuc va, loc va
cua te » cua tu

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 ((le lang) OR (le dang)) xa hoi. hieu va cam ((luc va) or (duc va)) hanh hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((le lang) OR (le dang)) xa hoi. hieu va cam ((luc va) OR (duc va)) hanh hai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((le lang) OR (le dang)) xa hoi. hieu va cam ((luc va) or (duc va)) hanh hai cua te".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((le lang) OR (le dang)) xa hoi. hieu va cam ((luc va) or (duc va)) hanh hai cua te*.