Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cau phuc » cau truc, chau phu, huu phuc
hanh vai » hanh vi, hanh va, hanh tai
sang cho » danh cho, dung cho, sang tao
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, dua tren
va hanh » van hanh, va thanh, va danh
phuc va » phuc vu, thuc va, chuc va
so sach » so sanh, bo sach, co sach
nang co » nang cao, nang doc, nang noi
van cau » van dau, van hau, van chat

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 hanh vai ((cua tre) OR (cua triet))~.
• 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 hanh vai ((cua tre) OR (cua triet)).
• 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 hanh vai ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: so sach y ((nang co) or (sang cho)) hoi. hieu van cau phuc va hanh vai ((cua tre) OR (cua triet))*.