Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
va thanh » gia thanh, ban thanh, va tinh
thanh vi » hanh vi, thanh va, thanh ve
ve triet » va trien, su triet
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
ve cac » vien cac
cua tu » cua tuc, cua su, cua cu
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: doc sach y nang o hoi. hieu ((va cac) or (ve cac)) duc va thanh vi ((cua tu) or (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach y nang o hoi. hieu ((va cac) OR (ve cac)) duc va thanh vi ((cua tu) OR (ve triet)).
• Adding a wildcard symbol may retrieve word variants: doc sach y nang o hoi. hieu ((va cac) or (ve cac)) duc va thanh vi ((cua tu) or (ve triet))*.