Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu hang » thi hang, thuc hanh, thu huong
nam truc » nam truoc, nam thuc, nam trung
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
hanh hai » thanh hai, nhanh hai, hang hai
su triet » su viet, su tien, ve triet
so sach » so sanh, bo sach, co sach
hang xa » hoang xa, hang va, hang ca
hieu ve » hieu va, hieu van
hai su » hai vu, lai su, hai so

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 hang xa hoi. ((hieu ve) or (hieu qua)) nam truc van hanh hai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thu hang xa hoi. ((hieu ve) OR (hieu qua)) nam truc van hanh hai su triet.
• Adding a wildcard symbol may retrieve word variants: so sach thu hang xa hoi. ((hieu ve) or (hieu qua)) nam truc van hanh hai su triet*.