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