Perhaps you should try some spelling variations:
vien canh » bien canh, vien can, vien nganh
canh thuc » anh thuc, cach thuc, danh thuc
hieu vien » hieu hien, hieu viec, thieu nien
su triet » su viet, ve triet
van hang » van khang, van hoang, van thang
dang xay » dang van, van xay
thuc van » thuc vat, thuc dan, thuc va
hang ki » hang di, hang ke, hang vi
su sach » so sach, vu sach
lang xa » lang ha, lang van
su tien » su kien, su hien, tu tieng
sach v » sach va, sach y, sach 2

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach v ((lang xa) or (dang xay)) hoi. hieu vien canh thuc van hang ki ((su triet) OR (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v ((lang xa) OR (dang xay)) hoi. hieu vien canh thuc van hang ki ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v ((lang xa) or (dang xay)) hoi. hieu vien canh thuc van hang ki ((su triet) OR (su tien))".
• Adding a wildcard symbol may retrieve word variants: su sach v ((lang xa) or (dang xay)) hoi. hieu vien canh thuc van hang ki ((su triet) OR (su tien))*.