Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
phan lap » phan dau
phan tap » han tap, pha tap, phan tu
truc van » thuc van, truc ban, truc dan
hieu su » hieu sau, tieu su, hieu so
su cham » su pham, tu cham, vu cham
sach ty » sach y, sach tu, sach thu
truc va » thuc va, thuc vat, trung va
nang ho » nang hoc, nang co, tang ho
ty nang » ky nang, ty xang, ty hang
tu sach » thu sach, su sach, te sach
ho hoi » hoc hoi, hoa hoi, hoi 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. hieu su cham ((truc van) OR (truc va)) ((phan tap) or (phan lap)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ho hoi. hieu su cham ((truc van) OR (truc va)) ((phan tap) OR (phan lap)) va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ho hoi. hieu su cham ((truc van) OR (truc va)) ((phan tap) or (phan lap)) va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ho hoi. hieu su cham ((truc van) OR (truc va)) ((phan tap) or (phan lap)) va triet*.