Perhaps you should try some spelling variations:
su sach » so sach, vu sach
thi cuu » thi cuc, thi huu, thi cu
dau thi » cau thi, dan thi, dao thi
cac toc » cac toi, cac nuoc, cac thoi
sach ky » sac ky, sach y, sach ty
cac tuc » cac tu, cac tac, cac nuoc
nang xa » nang x, lang xa, nang ma
lang ha » long ha
cuu tre » cua tre, cau tren, cau treo
va dau » va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang xa) or (lang ha)) hoi. lieu va ((cac tuc) or (cac toc)) va dau thi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (lang ha)) hoi. lieu va ((cac tuc) OR (cac toc)) va dau thi cuu tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (lang ha)) hoi. lieu va ((cac tuc) or (cac toc)) va dau thi cuu tre*.