Perhaps you should try some spelling variations:
van cham » van chat, van tham, va cham
hieu van » hieu va, thien van, lieu va
pho cua » cho cua, kho cua, tho cua
thuc va » thuc vat, thuc dan, thuc day
truc va » thuc vat, trung va
tu sach » thu sach, su sach, te sach
ly nang » ky nang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu hoach)) ly nang o hoi. hieu van cham ((truc va) or (thuc va)) thanh pho cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu hoach)) ly nang o hoi. hieu van cham ((truc va) OR (thuc va)) thanh pho cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu hoach)) ly nang o hoi. hieu van cham ((truc va) or (thuc va)) thanh pho cua tre*.