Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh duc » thach duc, than duc, thinh duc
thanh doi » thanh loi, thanh moi, thanh do
sach vuc » sach duoc, sach nuoc, sach truc
vuc nang » cuc nang, vu nang, chuc nang
hieu van » hieu va, thien van, lieu va
hanh doi » hanh noi, hang doi, hanh moi
su sach » so sach, vu sach
cao hoc » co hoc, cho hoc, chat hoc
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: su sach vuc nang cao hoc. hieu van thanh duc va ((hanh doi) or (thanh doi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach vuc nang cao hoc. hieu van thanh duc va ((hanh doi) OR (thanh doi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach vuc nang cao hoc. hieu van thanh duc va ((hanh doi) or (thanh doi)) cua tre*.