Perhaps you should try some spelling variations:
nang xa » nang x, lang xa, nang ma
sach ty » sach tu, sach thu, xach tay
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
va vanh » va van, va danh, va hanh
tai cao » thai cao, tai sao, tai cac
tao cao » bao cao, toan cao
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach y) or (sach ty)) nang xa hoi. hieu va cam duc va vanh ((tai cao) OR (tao cao)) trieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach y) OR (sach ty)) nang xa hoi. hieu va cam duc va vanh ((tai cao) OR (tao cao)) trieu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach y) or (sach ty)) nang xa hoi. hieu va cam duc va vanh ((tai cao) OR (tao cao)) trieu".
• Adding a wildcard symbol may retrieve word variants: thu ((sach y) or (sach ty)) nang xa hoi. hieu va cam duc va vanh ((tai cao) OR (tao cao)) trieu*.