Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
phan tap » phan lap, han tap, pha tap
truc van » thuc van, truc ban, truc dan
truc va » thuc va, thuc vat, trung va
vu cham » va cham, vu kham, tu cham
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
hoc hoi » hoc khoi, hoc hoa, hoc noi
ty nang » ky nang, ty xang, ty hang
hieu vu » hieu va, hieu ve, hieu su
ho hoi » hoa hoi, hoi hoi, co hoi

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 ty nang ((ho hoi) or (hoc hoi)). hieu vu cham ((truc van) OR (truc va)) phan tap va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((ho hoi) OR (hoc hoi)). hieu vu cham ((truc van) OR (truc va)) phan tap va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((ho hoi) or (hoc hoi)). hieu vu cham ((truc van) OR (truc va)) phan tap va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((ho hoi) or (hoc hoi)). hieu vu cham ((truc van) OR (truc va)) phan tap va triet*.