Perhaps you should try some spelling variations:
te sach » toc sach
hoc cac » hoc cao
han tai » hang tai, nhan tai, van tai
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
xac va » tac va, ac va, bac va
tuc va » thuc va, truc va, tuc xa
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) or (hoc cac)) ky nang x hoi. lieu va cam ((xac va) or (tuc va)) han tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (hoc cac)) ky nang x hoi. lieu va cam ((xac va) OR (tuc va)) han tai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (hoc cac)) ky nang x hoi. lieu va cam ((xac va) or (tuc va)) han tai cua tre*.