Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
sach hay » sach han, sach ha, sach nay
lang hoa » hang hoa, lang ha, nang hoa
va thanh » gia thanh, ban thanh, va tinh
sach tay » xach tay, sach nay, sach tai
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
cau tuc » cau truc, cau tu, cau luc
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
hoa hoi » khoa hoi, hoa hoc, hoa doi
tuc va » thuc va, truc va, tuc xa

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 tay) OR (sach hay)) lang hoa hoi. ((hieu ve) or (hieu va)) cau tuc va thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tay) OR (sach hay)) lang hoa hoi. ((hieu ve) OR (hieu va)) cau tuc va thanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach tay) OR (sach hay)) lang hoa hoi. ((hieu ve) or (hieu va)) cau tuc va thanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach tay) OR (sach hay)) lang hoa hoi. ((hieu ve) or (hieu va)) cau tuc va thanh vai cua tre*.