Perhaps you should try some spelling variations:
sua viet » su viet, cua viet, lua viet
cam thuc » am thuc, nam thuc, cam thu
hang tai » hang va, dung tai
hanh tai » thanh tai, han tai, hinh tai
thuc van » thuc vat, thuc dan, thuc va
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao

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 (vu bach)) ky tang ma hoi. hieu va cam thuc van ((hanh tai) or (hang tai)) sua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (vu bach)) ky tang ma hoi. hieu va cam thuc van ((hanh tai) OR (hang tai)) sua viet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (vu bach)) ky tang ma hoi. hieu va cam thuc van ((hanh tai) or (hang tai)) sua viet*.