Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
hanh lai » hanh lam, hanh tai, thanh lap
lai dau » lam dau, lan dau, lai chau
sach tu » sach thu, cach tu, sach ty
tu sach » thu sach, su sach, te sach
hieu so » thieu so
tao hoi » tao khoi, tay hoi, thao hoc
tu sang » thu sang, tu san, tu lang
so cham » so kham, co cham, so chat
soc va » hoc va, doc va, goc va
loc va » hoc va, luc va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu sang ((tao hoi) OR (tao boi)). hieu so cham ((soc va) OR (loc va)) hanh lai dau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu sang ((tao hoi) OR (tao boi)). hieu so cham ((soc va) or (loc va)) hanh lai dau tren~".
• Adding a wildcard symbol may retrieve word variants: tu sach tu sang ((tao hoi) OR (tao boi)). hieu so cham ((soc va) or (loc va)) hanh lai dau tren*.