Perhaps you should try some spelling variations:
dinh dien » tinh dien, kinh dien, dich dien
van dinh » van minh, van dich, va dinh
te sach » toc sach
hoc van » hoc dan, hoc va, hoc vat
va chat » van chat, va phat, cao chat
va cham » va tham
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
sach v » sach va, sach y, sach 2
tu te » tu tu, tu le

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 v ((nang xa) or (lang xa)) hoi. hieu ((va cham) OR (va chat)) hoc van dinh dien tu te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach v ((nang xa) OR (lang xa)) hoi. hieu ((va cham) OR (va chat)) hoc van dinh dien tu te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach v ((nang xa) or (lang xa)) hoi. hieu ((va cham) OR (va chat)) hoc van dinh dien tu te".
• Adding a wildcard symbol may retrieve word variants: te sach v ((nang xa) or (lang xa)) hoi. hieu ((va cham) OR (va chat)) hoc van dinh dien tu te*.