Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
hanh lai » hanh lam, hanh tai, thanh lap
so sach » so sanh, bo sach, co sach
chuc va » thuc va
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu van
chau te » chau tho
ma hoi » mai hoi, xa hoi, ma hoa

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