Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
cua viet » ca viet, hoa viet, cua vat
thuc dan » thuc hanh, hoc dan, thuc vat
khanh di » khanh bui, khanh duy, hanh de
nam thuc » nam thuoc, am thuc, nam thu
hieu he » hieu ve, hiem he, hieu le
nang xa » nang x, lang xa, nang ma
su sach » so sach
vu sach » vu bach, vu khach
he nam » ha nam, nghe nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (su sach)) ky nang xa hoi. hieu he nam thuc dan ((khanh di) OR (thanh doi)) cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (su sach)) ky nang xa hoi. hieu he nam thuc dan ((khanh di) OR (thanh doi)) cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (su sach)) ky nang xa hoi. hieu he nam thuc dan ((khanh di) OR (thanh doi)) cua viet".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (su sach)) ky nang xa hoi. hieu he nam thuc dan ((khanh di) OR (thanh doi)) cua viet*.