Perhaps you should try some spelling variations:
sinh thai » dinh thi
thu sach » tu sach, thuat sach, thuoc sach
thai cua » than cua, tai cuc, tri cua
hieu va » lieu va, hieu qua
va sinh » va kinh, va tinh, vi sinh
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
hieu ve » hieu van
ty sang » ty xang, ty hang, duy sang
xu va » xu van, tu va, su va

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 ty sang ((ma hoa) or (xa hoi)). ((hieu ve) or (hieu va)) chao xu va sinh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty sang ((ma hoa) OR (xa hoi)). ((hieu ve) OR (hieu va)) chao xu va sinh thai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ty sang ((ma hoa) or (xa hoi)). ((hieu ve) or (hieu va)) chao xu va sinh thai cua tre*.