Perhaps you should try some spelling variations:
trinh dieu » trinh dien, tinh dieu, trinh dinh
hieu van » hieu va, thien van, lieu va
dieu tra » dieu tri, kiem tra, dieu cua
va trinh » van trinh, va tinh, lap trinh
luat tuc » luat thue
so sach » so sanh, bo sach, co sach
lam tuc » lam thuoc, lam truoc, nam thuc
pho hai » pho ha
y nang » ky nang, ly nang, v nang
ho hai » hoc hai, cho hai, ho hap
tra te » tra tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang ((ho hai) OR (pho hai)). hieu van ((lam tuc) or (luat tuc)) va trinh dieu tra te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang ((ho hai) OR (pho hai)). hieu van ((lam tuc) OR (luat tuc)) va trinh dieu tra te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y nang ((ho hai) OR (pho hai)). hieu van ((lam tuc) or (luat tuc)) va trinh dieu tra te".
• Adding a wildcard symbol may retrieve word variants: so sach y nang ((ho hai) OR (pho hai)). hieu van ((lam tuc) or (luat tuc)) va trinh dieu tra te*.