Perhaps you should try some spelling variations:
hoc quoc » hoc nuoc, hoc duoc, hoc thuoc
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, chat xuc
dan vai » dan va, dan tai, dan vat
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
tu san » thu san, tu ban, tu can
san ky » sang ky, van ky, dan ky
va dan » ca dan, va dao, va dau
ky va » ly va, ke va, my va
va xa » va xac, va xay, va xu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu san ky va xa hoi. hieu va ((cac xuc) or (hoc quoc)) va dan vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu san ky va xa hoi. hieu va ((cac xuc) OR (hoc quoc)) va dan vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu san ky va xa hoi. hieu va ((cac xuc) or (hoc quoc)) va dan vai cua tre*.