Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
thu sach » tu sach, thuat sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
ty nang » ty xang, ty hang, ly nang
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thuat
thuc va » thuc vat, thuc dan, thuc day
thiet » thieu

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