Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nha thuoc, cay thuoc
hieu van » hieu va, thien van, lieu va
hanh hai » thanh hai, nhanh hai, hang hai
hai cua » thai cua, dai cua, hoi cua
xa hanh » xa thanh, xa khanh, va hanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky sang » ky nang, ky dang, ky tang
ma hoi » mai hoi, xa hoi, me hoi
cua te » cua tu

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

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