Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
su triet » su viet, ve triet
ban hanh » ban hang
cham luu » cham cuu, chat lua, phap luu
tu sach » su sach, te sach, tu cach
vu cham » va cham, vu kham, tu cham
luu ban » luu bang, luu van, luu dan
hieu vu » hieu va, hieu ve, hieu su
hang ca » hang va, nang cao, hang tai
ty hang » ly hang, ty xang, thi hang
su tien » su kien, su hien, tu tieng
ca hoi » cau hoi, cua hoi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) ty hang ca hoi. hieu vu cham luu ban hanh vi ((su triet) OR (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty hang ca hoi. hieu vu cham luu ban hanh vi ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ty hang ca hoi. hieu vu cham luu ban hanh vi ((su triet) OR (su tien))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ty hang ca hoi. hieu vu cham luu ban hanh vi ((su triet) OR (su tien))*.