Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, tu cach
hieu va » lieu va, hieu qua
te sach » toc sach
nang xa » nang x, lang xa, mang xa
dinh va » dinh van, dinh ve, tinh va
va dinh » van dinh, va kinh, va tinh
nang ma » tang ma, sang ma, nang cao
va chao » va cao, va chat, va cham
va cua » va chua, via cua, ca cua
cua te » cua tu
xu va » xu van, tu va, su va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (te sach)) ky ((nang xa) OR (nang ma)) hoi. hieu va chao xu va dinh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky ((nang xa) OR (nang ma)) hoi. hieu va chao xu va dinh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky ((nang xa) OR (nang ma)) hoi. hieu va chao xu va dinh va cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky ((nang xa) OR (nang ma)) hoi. hieu va chao xu va dinh va cua te*.