Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
dan hang » ban hang, van hang, dat hang
hang hai » hoang hai, hang tai, thanh hai
cua viet » ca viet, hoa viet, cua dieu
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu he » hieu ve, hiem he, hieu hien
hieu le » hieu ve, hieu ly, tieu le

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 ky nang xa hoi. ((hieu he) OR (hieu le)) nam thuc dan hang hai ((cua viet) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang xa hoi. ((hieu he) OR (hieu le)) nam thuc dan hang hai ((cua viet) OR (cua vat))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang xa hoi. ((hieu he) OR (hieu le)) nam thuc dan hang hai ((cua viet) or (cua vat))*".