Perhaps you should try some spelling variations:
doc thuc » hoc thuc, do thuc, hoc thuoc
trinh va » trinh van, trinh vat, trinh ve
trong ca » trong cac, trong nha
su sach » so sach, vu sach
tinh vi » trinh vi, tinh voi, tinh va
thuc va » thuc vat, thuc dan, thuc day
hieu me » hieu ve, hieu he, hieu le
sach ty » sach y, sach tu, sach thu
tang xa » trang xa, tang ma, lang xa
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: su sach ty ((tang xa) OR (trong ca)) hoi. hieu me doc thuc va ((tinh vi) OR (trinh va)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((tang xa) OR (trong ca)) hoi. hieu me doc thuc va ((tinh vi) OR (trinh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((tang xa) OR (trong ca)) hoi. hieu me doc thuc va ((tinh vi) OR (trinh va)) cua tre*.