Perhaps you should try some spelling variations:
chau triet » cau triet, cua triet, cau trieu
hanh tai » thanh tai, hang tai, han tai
hanh lai » hanh lam, thanh lap, thanh loi
phan duc » pham duc, phan tu, phan dau
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
ve phan » va phan, ke phan, ve phat

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