Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, va tinh, le thanh
dua tren » dung tren
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
van cam » van nam, van lam, van cau
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang o hoi. hieu van cam xuc ((va thanh) or (ban thanh)) lay ((dua tren) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang o hoi. hieu van cam xuc ((va thanh) OR (ban thanh)) lay ((dua tren) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang o hoi. hieu van cam xuc ((va thanh) or (ban thanh)) lay ((dua tren) or (cua triet))*.