Perhaps you should try some spelling variations:
hieu quan » hieu qua, lieu quan, thien quan
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
quan nam » quang nam, xuan nam, quan am
nam thuc » nam thuoc, am thuc, nam thu
vat dan » va dan, van dan, vat ran
vai cua » hai cua, lai cua, bai cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (doc sach)) ky nang x hoi. hieu quan nam thuc vat dan ((vai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky nang x hoi. hieu quan nam thuc vat dan ((vai cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ky nang x hoi. hieu quan nam thuc vat dan ((vai cua) or (dai cua)) tre*.