Perhaps you should try some spelling variations:
chet duoc » cho duoc, che quoc, chi duoc
cua triet » cua viet, su triet, va triet
che duoc » che thuoc, che do, te duoc
te sach » toc sach
su viet » so viet
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
sach v » sach va, sach y, sach 2
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
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: te sach v nang ma hoa. hieu va ((chet duoc) OR (che duoc)) va dan vi ((cua triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach v nang ma hoa. hieu va ((chet duoc) OR (che duoc)) va dan vi ((cua triet) OR (su viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach v nang ma hoa. hieu va ((chet duoc) OR (che duoc)) va dan vi ((cua triet) or (su viet))".
• Adding a wildcard symbol may retrieve word variants: te sach v nang ma hoa. hieu va ((chet duoc) OR (che duoc)) va dan vi ((cua triet) or (su viet))*.