Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
hanh doi » thanh doi, hanh noi, hang doi
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
doi cau » doi dau, di cau, doi ca
soc va » loc va, doc va, goc va
5 hoi » o hoi

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: su sach ky nang ((5 hoi) OR (x ho)). hieu qua cham ((soc va) OR (hoc va)) hanh doi cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((5 hoi) or (x ho)). hieu qua cham ((soc va) OR (hoc va)) hanh doi cau tren~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((5 hoi) or (x ho)). hieu qua cham ((soc va) OR (hoc va)) hanh doi cau tren*.