Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vi » hanh vi, thanh va, thanh ve
su sach » vu sach
qua ban » cua ban, qua quan
cam qua » cau qua, cac qua, cay qua
qua cam » qua cham, qua cac, qua ca
hang ca » hang va, nang cao, hang tai
ty hang » ly hang, ty xang, thi hang
so sach » so sanh, bo sach, co sach
ca hoi » cau hoi, cua hoi, xa hoi
cua tu » cua tuc, cua su, cua cu

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) or (so sach)) ty hang ca hoi. hieu qua cam qua ban thanh vi ((cua te) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ty hang ca hoi. hieu qua cam qua ban thanh vi ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ty hang ca hoi. hieu qua cam qua ban thanh vi ((cua te) OR (cua tu))".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ty hang ca hoi. hieu qua cam qua ban thanh vi ((cua te) OR (cua tu))*.