Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
thuc va » thuc vat, thuc dan, thuc day
van cam » van nam, van lam, van cau
ly hang » ly quang
ly nang » ky nang, ly vang, ly quang
cuu tre » cua tre, cau tren, cau treo
tuc va » truc va, tuc xa, duc va
vi cuu » vi luu, vinh cuu

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