Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
va thanh » gia thanh, ban thanh, va tinh
thu sach » tu sach, thuat sach, thuoc sach
cao hoi » cau hoi, co hoi, cao hoc
ty hang » ly hang, ty xang, thi hang
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
ty nang » ky nang, ty xang, ly nang
va nham » va cham, va tham, va nha
va vai » va bai, va van, va dai
va va » va van, va vua, va vat

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ty nang) OR (ty hang)) cao hoi. hieu va nham thuc va thanh ((va va) or (va vai)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty nang) OR (ty hang)) cao hoi. hieu va nham thuc va thanh ((va va) OR (va vai)) thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ty nang) OR (ty hang)) cao hoi. hieu va nham thuc va thanh ((va va) or (va vai)) thiet".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty nang) OR (ty hang)) cao hoi. hieu va nham thuc va thanh ((va va) or (va vai)) thiet*.