Perhaps you should try some spelling variations:
ban hanh » ban hang
ban danh » ban doanh, ban dan, van danh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
cam cuu » cham cuu, cap cuu
hieu va » lieu va, hieu qua
hieu ve » hieu van
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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 ky lang xa hoi. ((hieu ve) OR (hieu va)) cam cuu ((ban danh) or (ban hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang xa hoi. ((hieu ve) OR (hieu va)) cam cuu ((ban danh) OR (ban hanh)) vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky lang xa hoi. ((hieu ve) OR (hieu va)) cam cuu ((ban danh) or (ban hanh)) vi cua tre*".