Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van chat » cao chat
dung sai » dung tai, dung va, dung dat
danh sai » danh bat, danh dau, hanh san
cua tre » cua te, cuu tre, cua triet
thuc va » thuc vat, thuc dan, thuc day
truc va » thuc vat, trung va
cao hoi » cau hoi, co hoi, cao hoc
y nang » ky nang, ly nang, v nang

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

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