Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
phan lap » phan dau
truc van » thuc van, truc ban, truc dan
truc va » thuc va, thuc vat, trung va
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
hieu vu » hieu ve, hieu su, dieu vu
nang ho » nang hoc, nang co, tang ho
ty nang » ky nang, ty xang, ty hang
hieu va » lieu va, hieu qua
ho hoi » hoc hoi, hoa hoi, hoi hoi
lap va » tap va

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