Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, hoc sach, cuoc cach
doc sach » hoc sach, toc sach, dac sac
nam thuc » nam thuoc, am thuc, nam thu
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
vat dan » va dan, van dan, vat ran
vai cuu » vai cua
va nam » van nam, ha nam, va nay

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc sach) OR (nuoc sach)) ky nang xa hoi. hieu va nam thuc vat dan ((vai cuu) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (nuoc sach)) ky nang xa hoi. hieu va nam thuc vat dan ((vai cuu) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc sach) OR (nuoc sach)) ky nang xa hoi. hieu va nam thuc vat dan ((vai cuu) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((doc sach) OR (nuoc sach)) ky nang xa hoi. hieu va nam thuc vat dan ((vai cuu) or (dai cua)) tre*.