Perhaps you should try some spelling variations:
thien van » thi van
hanh doi » thanh doi, hanh noi, hang doi
cam thuc » am thuc, nam thuc, cam thu
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
doi cua » dai cua, hoi cua
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu hoach)) ky nang ma hoi. ((hieu va) or (thien van)) cam thuc va hanh doi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu hoach)) ky nang ma hoi. ((hieu va) OR (thien van)) cam thuc va hanh doi cua vat.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu hoach)) ky nang ma hoi. ((hieu va) or (thien van)) cam thuc va hanh doi cua vat*.