Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thuc day » thuc dan, thuc vat
hanh hai » thanh hai, nhanh hai, hang hai
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van cau » van dau, van hau, van chat
truc va » thuc va, thuc vat, trung va
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren

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 ky nang xa hoi. hieu van cau ((truc va) or (thuc day)) hanh hai ((cuu tre) OR (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. hieu van cau ((truc va) OR (thuc day)) hanh hai ((cuu tre) OR (cua tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang xa hoi. hieu van cau ((truc va) or (thuc day)) hanh hai ((cuu tre) OR (cua tre))".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. hieu van cau ((truc va) or (thuc day)) hanh hai ((cuu tre) OR (cua tre))*.