Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sang cho » danh cho, dung cho, sang tao
van cau » van dau, van hau, van chat
chuc va » thuc va, thuc vat
phuc va » phuc vu, thuc va, thuc vat
so sach » so sanh, bo sach, co sach
nang co » nang cao, nang doc, nang noi
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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

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