Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
vu sach » vu bach, su sach, vu khach
sach ty » sach y, sach tu, sach thu
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
ca viet » va viet, co viet, hoa viet
cam thu » nam thu, cac thu, ca thu
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
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: vu sach ty nang ma hoi. hieu va ((cam thu) or (nam thuc)) va hanh va ((cua vat) or (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty nang ma hoi. hieu va ((cam thu) OR (nam thuc)) va hanh va ((cua vat) OR (ca viet)).
• Adding a wildcard symbol may retrieve word variants: vu sach ty nang ma hoi. hieu va ((cam thu) or (nam thuc)) va hanh va ((cua vat) or (ca viet))*.