Perhaps you should try some spelling variations:
lam thuoc » nam thuoc, am thuc, cay thuoc
va triet » va thiet, va trien, ve triet
lam thuc » am thuc, nam thuc, dam thuc
tinh vai » tinh va, tinh hai, tinh bai
hieu van » hieu va, thien van, hieu ve
va tinh » may tinh
te sach » toc sach
sach ly » sach y, sach lo, sach ty
nang ma » tang ma, sang ma, nang cao
ly nang » ky nang, ly hang, ly vang
ma hoi » mai hoi, xa hoi, ma hoa
vai va » mai va, dai va, hai va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ly nang ma hoi. ((hieu van) or (lieu va)) ((lam thuc) OR (lam thuoc)) va tinh vai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ly nang ma hoi. ((hieu van) OR (lieu va)) ((lam thuc) OR (lam thuoc)) va tinh vai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ly nang ma hoi. ((hieu van) or (lieu va)) ((lam thuc) OR (lam thuoc)) va tinh vai va triet".
• Adding a wildcard symbol may retrieve word variants: te sach ly nang ma hoi. ((hieu van) or (lieu va)) ((lam thuc) OR (lam thuoc)) va tinh vai va triet*.