Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
dua tren » dung tren
te sach » toc sach
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cua triet, cua thep
cuu tre » cau tren, cau treo
va cam » va cham, va cac, va cao

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 thu nang x ho. hieu va cam duc va hanh vi ((((cua tre) OR (dua tren))) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thu nang x ho. hieu va cam duc va hanh vi ((((cua tre) OR (dua tren))) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thu nang x ho. hieu va cam duc va hanh vi ((((cua tre) OR (dua tren))) or (cuu tre))*".