Perhaps you should try some spelling variations:
nay thuoc » cay thuoc, nam thuoc, na thuoc
vat thanh » dat thanh, gat thanh, tat thanh
ta thanh » tai thanh, va thanh, ha thanh
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu 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: so sach ky nang xa hoi. ((hieu va) OR (lieu va)) nay thuoc ((vat thanh) or (ta thanh)) dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang xa hoi. ((hieu va) OR (lieu va)) nay thuoc ((vat thanh) OR (ta thanh)) dai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang xa hoi. ((hieu va) OR (lieu va)) nay thuoc ((vat thanh) or (ta thanh)) dai cua te".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang xa hoi. ((hieu va) OR (lieu va)) nay thuoc ((vat thanh) or (ta thanh)) dai cua te*.