Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
lam thuc » lam thuoc, am thuc, nam thuc
tinh vai » tinh va, tinh hai, tinh bai
va triet » va thiet, va trien, ve triet
nang ma » tang ma, sang ma, nang cao
van lam » van nam
thuc va » thuc vat, thuc dan, thuc day
va tinh » may tinh
y nang » ky nang, ly nang, v nang
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) OR (toc sach)) y nang ma hoi. hieu van lam thuc va tinh vai va triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) y nang ma hoi. hieu van lam thuc va tinh vai va triet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) y nang ma hoi. hieu van lam thuc va tinh vai va triet*.