Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh lam » thanh lap, hanh lam, thanh nam
hieu van » hieu va, thien van, lieu va
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cau duc » cao duc, cau luc, cau truc
chu duc » thu duc, chua duoc, cuu duoc
nang o » nang co, nang ho, nang ro
lam su » lai su, lam so, lam vu
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 van ((cau duc) OR (chu duc)) ban thanh lam su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang o hoi. hieu van ((cau duc) OR (chu duc)) ban thanh lam su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o hoi. hieu van ((cau duc) OR (chu duc)) ban thanh lam su triet*.