Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
hoc sach » hoc sinh, hoc cac, hoc anh
co sach » bo sach, cuon sach
nang ma » tang ma, sang ma, nang cao
va tham » van tham, va cham, va thanh
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
su viet » so viet
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: ((hoc sach) or (co sach)) ky nang ma hoi. lieu va tham thuc ((va hanh) or (va danh)) va su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (co sach)) ky nang ma hoi. lieu va tham thuc ((va hanh) OR (va danh)) va su viet.
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (co sach)) ky nang ma hoi. lieu va tham thuc ((va hanh) or (va danh)) va su viet*.