Perhaps you should try some spelling variations:
trinh viet » trinh vat
ninh viet » sinh vien, anh viet
vu sach » vu bach, su sach, vu khach
xang xa » lang xa, ang xa, dang xay
mang xa » lang xa, mang may, dang xay
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
cam luc » cam xuc, cau luc
luc van » luoc van, luu van, duc van
va cam » va cham, va cac, va cao
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ty ((xang xa) OR (mang xa)) hoi. hieu va cam luc van ((trinh viet) or (ninh viet)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty ((xang xa) OR (mang xa)) hoi. hieu va cam luc van ((trinh viet) OR (ninh viet)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty ((xang xa) OR (mang xa)) hoi. hieu va cam luc van ((trinh viet) or (ninh viet)) cua te".
• Adding a wildcard symbol may retrieve word variants: vu sach ty ((xang xa) OR (mang xa)) hoi. hieu va cam luc van ((trinh viet) or (ninh viet)) cua te*.