Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
hanh ve » hanh vi, hanh va, hanh kem
duc ban » duc tan, duc van, dua ban
cuc ban » cua ban, cac ban, cuu ban
te sach » toc sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
ve cac » va cac
ve cua » le cua, de cua, te cua
x hoi » xa hoi, o hoi, x ho

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 ky nang x hoi. hieu ((ve cac) OR (vien cac)) ((cuc ban) or (duc ban)) hanh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang x hoi. hieu ((ve cac) OR (vien cac)) ((cuc ban) OR (duc ban)) hanh ve cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang x hoi. hieu ((ve cac) OR (vien cac)) ((cuc ban) or (duc ban)) hanh ve cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang x hoi. hieu ((ve cac) OR (vien cac)) ((cuc ban) or (duc ban)) hanh ve cua tre*.