Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, thai thuc
van hanh » van thanh, ban hanh, van anh
tham xuc » tham nuoc, pham duc, cam xuc
tam thuc » am thuc, nam thuc, dam thuc
tu sach » thu sach, su sach, te sach
hanh ki » hanh vi, hanh ky, hanh kien
su viet » so viet
sach tu » sach thu, cach tu, sach ty
nang ma » tang ma, sang ma, nang cao
tu nang » tru nang, tu nong, tu nano
ma hoi » mai hoi, xa hoi, ma hoa
ki su » ky su

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 tu nang ma hoi. hieu qua ((tham xuc) or (((tham thuc) OR (tam thuc)))) van hanh ki su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu nang ma hoi. hieu qua ((tham xuc) OR (((tham thuc) OR (tam thuc)))) van hanh ki su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu nang ma hoi. hieu qua ((tham xuc) or (((tham thuc) OR (tam thuc)))) van hanh ki su viet".
• Adding a wildcard symbol may retrieve word variants: tu sach tu nang ma hoi. hieu qua ((tham xuc) or (((tham thuc) OR (tam thuc)))) van hanh ki su viet*.