Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
va trien » va truyen, va thiet, va tuyen
sach ky » sac ky, sach y, sach ty
luc van » luoc van, luu van, duc van
tu sach » thu sach, su sach, te sach
va nhan » van nhan, va phan, va nha
ban vi » ban voi, ban va, ban ve
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: tu sach ky nang o hoi. hieu ((va nhan) OR (ca nhan)) luc van ban vi ((va trien) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang o hoi. hieu ((va nhan) OR (ca nhan)) luc van ban vi ((va trien) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang o hoi. hieu ((va nhan) OR (ca nhan)) luc van ban vi ((va trien) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o hoi. hieu ((va nhan) OR (ca nhan)) luc van ban vi ((va trien) or (su triet))*.