Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nang mai » nang ma, nang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
vanh dai » van dai, vanh tai, lanh dao
cua tre » cua te, cuu tre, dua tren
va vanh » va van, va danh, va hanh
tu sach » thu sach, su sach, te sach
ke cau » ket cau
y nang » ky nang, ly nang, v nang
luc va » duc va, tuc va, loc va
ve cau » va cau, ve cac, le cau

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 mai khoi. hieu ((ve cau) OR (ke cau)) luc va vanh dai ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang mai khoi. hieu ((ve cau) OR (ke cau)) luc va vanh dai ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang mai khoi. hieu ((ve cau) OR (ke cau)) luc va vanh dai ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang mai khoi. hieu ((ve cau) OR (ke cau)) luc va vanh dai ((cua tre) or (cua triet))*.