Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
cam thuc » am thuc, nam thuc, cam thu
van hanh » van thanh, ban hanh, van anh
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va hanh » va thanh, va danh, ban hanh
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
vi cua » vai cua, di cua

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 (thu sach)) ky nang xa hoi. hieu va cam thuc ((va hanh) or (van hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang xa hoi. hieu va cam thuc ((va hanh) OR (van hanh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang xa hoi. hieu va cam thuc ((va hanh) or (van hanh)) vi cua tre*.