Perhaps you should try some spelling variations:
thuc day » thuc dan, thuc vat
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
tu sach » thu sach, su sach, te sach
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
truc va » thuc va, thuc vat, trung va
van cau » van dau, van hau, van chat
nang xa » nang x, lang xa, nang ma
y nang » ky nang, ly nang, v nang

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

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