Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van chat » cao chat
danh dai » danh dau, danh di, danh sai
sach ky » sac ky, sach y, sach ty
cao hoc » co hoc, cho hoc, chat hoc
truc va » thuc va, trung va
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang cao hoc. hieu van chat ((truc va) or (thuc vat)) danh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang cao hoc. hieu van chat ((truc va) OR (thuc vat)) danh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang cao hoc. hieu van chat ((truc va) or (thuc vat)) danh dai cua tre*.