Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
sach ky » sac ky, sach y, sach ty
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
sai ky » sac ky
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) or (sai ky)) nang xa hoi. hieu ve cam thuc ((va hanh) OR (va danh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sai ky)) nang xa hoi. hieu ve cam thuc ((va hanh) OR (va danh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sai ky)) nang xa hoi. hieu ve cam thuc ((va hanh) OR (va danh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sai ky)) nang xa hoi. hieu ve cam thuc ((va hanh) OR (va danh)) di cua tre*.