Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
su tien » su kien, su hien, tu tieng
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu vu » hieu va, hieu ve, dieu vu
hieu su » hieu sau, tieu su, hieu suat
thuc va » thuc vat, thuc dan, thuc day
hieu so » thieu so
dau vi » dau ve, dau va, dat vi
va dau » va dao
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
vi su » va su, ve su, ki su

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 ky dang xa hoi. ((hieu vu) or (((hieu su) OR (hieu so)))) pham thuc va dau vi su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky dang xa hoi. ((hieu vu) OR (((hieu su) OR (hieu so)))) pham thuc va dau vi su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky dang xa hoi. ((hieu vu) or (((hieu su) OR (hieu so)))) pham thuc va dau vi su tien".
• Adding a wildcard symbol may retrieve word variants: te sac ky dang xa hoi. ((hieu vu) or (((hieu su) OR (hieu so)))) pham thuc va dau vi su tien*.