Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
cac thuc » cach thuc, cac thu, can thuc
hang doi » hang di, hang loi, huong doi
hang don » hang ton, dang don, hang son
thuc van » thuc vat, thuc dan, thuc va
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
hang do » dang do, hang di, hang du
su sach » so sach, vu sach
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang

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