Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
chat truc » cau truc, chat xuc
hieu van » hieu va, thien van, lieu va
van chat » cao chat
vanh dai » van dai, vanh tai, lanh dao
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
truc va » thuc va, thuc vat, trung va
danh di » danh du, xanh di, danh dien
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach y ((nang xa) OR (lang xa)) hoi. hieu van chat truc va ((vanh dai) or (danh di)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y ((nang xa) OR (lang xa)) hoi. hieu van chat truc va ((vanh dai) OR (danh di)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach y ((nang xa) OR (lang xa)) hoi. hieu van chat truc va ((vanh dai) or (danh di)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat sach y ((nang xa) OR (lang xa)) hoi. hieu van chat truc va ((vanh dai) or (danh di)) cua tre*.