Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
nhan thuc » nhan luc, dan thuc, toan thuc
huu tre » huu tri, cuu tre, huu them
hieu va » lieu va, hieu qua
ky tang » ky nang, ky dang, kho tang
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, me hoi
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
va huu » vu huu
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky tang ((ma hoi) or (ma hoa)). hieu va ((nhan thuc) or (tham thuc)) va dan va huu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky tang ((ma hoi) OR (ma hoa)). hieu va ((nhan thuc) OR (tham thuc)) va dan va huu tre.
• Adding a wildcard symbol may retrieve word variants: tu sac ky tang ((ma hoi) or (ma hoa)). hieu va ((nhan thuc) or (tham thuc)) va dan va huu tre*.