Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
sach ty » sach y, sach tu, sach thu
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
te sach » toc sach
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
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: te sach ty nang xa hoi. ((hieu va) OR (lieu va)) cam thuc ((va hanh) or (va danh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang xa hoi. ((hieu va) OR (lieu va)) cam thuc ((va hanh) OR (va danh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang xa hoi. ((hieu va) OR (lieu va)) cam thuc ((va hanh) or (va danh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang xa hoi. ((hieu va) OR (lieu va)) cam thuc ((va hanh) or (va danh)) di cua tre*.