Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
vanh dai » van dai, vanh tai, lanh dao
qua cam » qua cham, qua cac, qua ca
cuu tre » cau tren, cau treo
va vanh » va van, va danh, va hanh
ty hang » ly hang, ty xang, thi hang
cua tre » cua te, cua triet, dua tren
xuc va » duc va, tuc va, luc va
hang x » nang x, hoang xa, chang xu
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ty hang x hoi. hieu qua cam xuc va vanh dai ((cuu tre) OR (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty hang x hoi. hieu qua cam xuc va vanh dai ((cuu tre) OR (cua tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ty hang x hoi. hieu qua cam xuc va vanh dai ((cuu tre) OR (cua tre))*".