Perhaps you should try some spelling variations:
doc thuc » hoc thuc, do thuc, hoc thuoc
trinh va » trinh van, trinh vat, trinh ve
trong xa » trong xay, trong ca, trong xu
sach thu » sach thue, sach thieu, sach tham
su sach » so sach, vu sach
tinh vi » trinh vi, tinh voi, tinh va
cua tre » cua te, cuu tre, cua triet
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
ve doc » ve duoc, va doc, me doc

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thu ((tang xa) or (trong xa)) hoi. hieu ve doc thuc va ((tinh vi) or (trinh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu ((tang xa) OR (trong xa)) hoi. hieu ve doc thuc va ((tinh vi) OR (trinh va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach thu ((tang xa) or (trong xa)) hoi. hieu ve doc thuc va ((tinh vi) or (trinh va)) cua tre*.