Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
va thanh » gia thanh, ban thanh, va tinh
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
de khoa » da khoa, ke khoa, te khoa
su sach » so sach, vu sach
de hoa » de hoan, do hoa, de hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (thu hoach)) ky nang cao hoi. hieu va tham thuc va thanh ((de hoa) or (de khoa)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thu hoach)) ky nang cao hoi. hieu va tham thuc va thanh ((de hoa) OR (de khoa)) viet.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thu hoach)) ky nang cao hoi. hieu va tham thuc va thanh ((de hoa) or (de khoa)) viet*.