Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hang doi » hang di, hang loi, huong doi
hang don » hang ton, dang don, hang do
thuc van » thuc vat, thuc dan, thuc va
cac thuc » cach thuc, cac thu, can thuc
van nang » van quang, van ban, van dong
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
vu sach » vu bach, vu khach
su sach » so sach

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) OR (vu sach)) van nang xa hoi. hieu va cac thuc van ((hang don) or (hang doi)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) van nang xa hoi. hieu va cac thuc van ((hang don) OR (hang doi)) su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (vu sach)) van nang xa hoi. hieu va cac thuc van ((hang don) or (hang doi)) su triet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (vu sach)) van nang xa hoi. hieu va cac thuc van ((hang don) or (hang doi)) su triet*.