Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
ban hanh » ban hang
ty nang » ky nang, ty xang, ty hang
hanh va » hang va, hanh vi
hieu ve » hieu van
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
lo ban » co ban, lo van, ly ban
va cua » va chua, via cua, ca cua
cam lo » nam lo, cam ly, cam o
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ty nang ((xa hoi) or (ma hoa)). ((hieu ve) OR (hieu va)) cam lo ban hanh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty nang ((xa hoi) OR (ma hoa)). ((hieu ve) OR (hieu va)) cam lo ban hanh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty nang ((xa hoi) or (ma hoa)). ((hieu ve) OR (hieu va)) cam lo ban hanh va cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ty nang ((xa hoi) or (ma hoa)). ((hieu ve) OR (hieu va)) cam lo ban hanh va cua te*.