Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cham duc » pham duc, cham soc, pham duy
hanh dao » lanh dao, thanh dat, thanh dam
sang tao » hang tai
sach duy » sach dung, sach duoc, sach dao
cua tre » cua te, cuu tre, dua tren
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
va cham » va chat, va tham
sang ma » tang ma, nang ma, mang may
hieu va » lieu va, hieu qua

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 duy ((sang ma) or (sang tao)) hoi. hieu va cham duc va hanh dao ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach duy ((sang ma) OR (sang tao)) hoi. hieu va cham duc va hanh dao ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach duy ((sang ma) or (sang tao)) hoi. hieu va cham duc va hanh dao ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach duy ((sang ma) or (sang tao)) hoi. hieu va cham duc va hanh dao ((cua tre) OR (cua triet))*.