Perhaps you should try some spelling variations:
chau triet » cau triet, cua triet, cau trieu
thanh lap » thanh san, phan lap, thanh hai
hanh lai » hanh lam, hanh tai, thanh loi
hieu van » hieu va, thien van, lieu va
hai duc » hoai duc, mai duc, ha duc
sach ky » sac ky, sach y, sach kem
nang ma » tang ma, sang ma, nang cao
sach ty » sach y, sach tu, sach thu
van hai » van ha, van chat, van hanh

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