Perhaps you should try some spelling variations:
sach thue » sach thieu, sach tham, cach thuc
khai cua » thai cua, hai cua, khi cua
dan khai » dang khai, van khai, dang khoi
cam truc » cau truc, nam truc, lam truoc
hieu van » hieu va, thien van, lieu va
sach thu » sach thieu, sach tham, cach thuc
truc ca » truc cau, truc va, truc cu
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
ca dan » cac dan, ca dao

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 thu) or (sach thue)) ((nang xa) or (nang ma)) hoi. hieu van cam truc ca dan khai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach thu) OR (sach thue)) ((nang xa) OR (nang ma)) hoi. hieu van cam truc ca dan khai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu ((sach thu) or (sach thue)) ((nang xa) or (nang ma)) hoi. hieu van cam truc ca dan khai cua tre*.