Perhaps you should try some spelling variations:
pham chuc » pham duc, pham huu, kham chua
nang mai » nang tai, lang mai, nang cai
hanh lai » hanh lam, hanh tai, thanh lap
sach thi » sach thu, sach tai, sach thieu
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
lai cua » dai cua, hai cua, lai chau
nang ma » tang ma, sang ma, nang cao
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va
chuc va » thuc va, thuc vat
cua te » cua tu

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 thi ((nang mai) or (nang ma)) hoi. ((hieu ve) OR (hieu van)) pham chuc va hanh lai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thi ((nang mai) OR (nang ma)) hoi. ((hieu ve) OR (hieu van)) pham chuc va hanh lai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach thi ((nang mai) or (nang ma)) hoi. ((hieu ve) OR (hieu van)) pham chuc va hanh lai cua te".
• Adding a wildcard symbol may retrieve word variants: so sach thi ((nang mai) or (nang ma)) hoi. ((hieu ve) OR (hieu van)) pham chuc va hanh lai cua te*.