Perhaps you should try some spelling variations:
thuoc dan » thuoc dang, thuc dan, thuoc ban
nam thuoc » nam thuc, nam thu, nha thuoc
cua viet » ca viet, hoa viet, cua vat
doc sach » hoc sach, toc sach, nuoc sach
nang hoa » nang hoat, hang hoa, nang hoc
hanh hai » thanh hai, nhanh hai, hang hai
dan hanh » dang hanh, dan khanh, dan thanh
hai cua » thai cua, dai cua, hoi cua
hoa hoi » khoa hoi, hoa hoc, hoa doi
hieu he » hieu ve, hiem he, hieu hien
hieu le » hieu ve, hieu ly, tieu le
te sac » te sach, te cac, te san

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sac) or (doc sach)) ky nang hoa hoi. ((hieu he) OR (hieu le)) nam thuoc dan hanh hai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sac) OR (doc sach)) ky nang hoa hoi. ((hieu he) OR (hieu le)) nam thuoc dan hanh hai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sac) or (doc sach)) ky nang hoa hoi. ((hieu he) OR (hieu le)) nam thuoc dan hanh hai cua viet".
• Adding a wildcard symbol may retrieve word variants: ((te sac) or (doc sach)) ky nang hoa hoi. ((hieu he) OR (hieu le)) nam thuoc dan hanh hai cua viet*.