Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
te sach » toc sach
va hanh » van hanh, va danh, ban hanh
cau luc » cau truc, cau phuc
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
di cua » dai cua, doi cua, de cua
va cau » van cau, va cac, va dau

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) or (lang xa)) hoi. hieu va cau luc ((va hanh) OR (va thanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((nang xa) OR (lang xa)) hoi. hieu va cau luc ((va hanh) OR (va thanh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((nang xa) or (lang xa)) hoi. hieu va cau luc ((va hanh) OR (va thanh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((nang xa) or (lang xa)) hoi. hieu va cau luc ((va hanh) OR (va thanh)) di cua tre*.