Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
thuc van » thuc vat, thuc dan, thuc va
dai thuc » dan thuc, dai thu, dai thua
hanh va » hang va, hanh vi
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
ty anh » ly anh, thuy anh
ty ang » ty xang, ty hang
va dai » va dao, vi dai, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ty ang) OR (ty anh)) xa hoi. hieu va dai thuc van ((anh va) or (hanh va)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty ang) OR (ty anh)) xa hoi. hieu va dai thuc van ((anh va) OR (hanh va)) cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ty ang) OR (ty anh)) xa hoi. hieu va dai thuc van ((anh va) or (hanh va)) cuu tre*".