Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
hieu va » lieu va, hieu qua
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: thu sach ky ((nang xa) or (nang x)) hoi. hieu va cac nuoc ((van hanh) OR (ban hanh)) dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (nang x)) hoi. hieu va cac nuoc ((van hanh) OR (ban hanh)) dai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((nang xa) or (nang x)) hoi. hieu va cac nuoc ((van hanh) OR (ban hanh)) dai cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (nang x)) hoi. hieu va cac nuoc ((van hanh) OR (ban hanh)) dai cua te*.