Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
te sach » toc sach
v nang » va nang, vu nang, van nang
sach v » sach va, sach y, sach 2
vi su » va su, ki su, oi su
ve su » va su

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

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