Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thi nang » thi cong, ki nang, thi hanh
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
nuoc van » nuoc va, nuoc san, luoc van
van hanh » van thanh, ban hanh, van anh
hanh vai » hanh vi, hanh va, hanh tai
te sach » toc sach
hieu ve » hieu va, hieu van
cua cau » cua cac, cua cay, cua can
cua chu » sua chua
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach thi nang ((x hoi) OR (x ho)). hieu ve cac nuoc van hanh vai ((cua cau) or (cua chu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thi nang ((x hoi) OR (x ho)). hieu ve cac nuoc van hanh vai ((cua cau) OR (cua chu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thi nang ((x hoi) OR (x ho)). hieu ve cac nuoc van hanh vai ((cua cau) or (cua chu))".
• Adding a wildcard symbol may retrieve word variants: te sach thi nang ((x hoi) OR (x ho)). hieu ve cac nuoc van hanh vai ((cua cau) or (cua chu))*.