Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
ve triet » va trien, su triet
hang tai » hang va, dung tai
tinh ve » trinh ve, tinh ven, dinh ve
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
ve cam » ve cham, ve cac, va cam
ve ve » de ve, va ve, ke ve

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thue ((nang ma) or (hang tai)) hoi. hieu ve cam ((luc va) OR (tuc va)) tinh ve ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thue ((nang ma) OR (hang tai)) hoi. hieu ve cam ((luc va) OR (tuc va)) tinh ve ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thue ((nang ma) or (hang tai)) hoi. hieu ve cam ((luc va) OR (tuc va)) tinh ve ve triet".
• Adding a wildcard symbol may retrieve word variants: su sach thue ((nang ma) or (hang tai)) hoi. hieu ve cam ((luc va) OR (tuc va)) tinh ve ve triet*.