Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
danh voi » hanh voi, lanh voi, hanh vi
may thoi » gay thoi, may thi, tay thoi
nam thuc » nam thuoc, am thuc, nam thu
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
hiem he » hiem xe, hieu he, thien he
mai hoi » mai khoi, dai hoi, lai hoi
may hoi » tay hoi, may hmi, may khoa
sach ky » sac ky, sach y, sach ty
voi hoa » voi hoat, voi khoa, boi hoa
he nam » ha nam, nghe nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky nang ((((may hoi) OR (may thoi))) or (mai hoi)). hiem he nam thuc va danh voi hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky nang ((((may hoi) OR (may thoi))) OR (mai hoi)). hiem he nam thuc va danh voi hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky nang ((((may hoi) OR (may thoi))) or (mai hoi)). hiem he nam thuc va danh voi hoa viet".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang ((((may hoi) OR (may thoi))) or (mai hoi)). hiem he nam thuc va danh voi hoa viet*.