Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
cong cua » cong cu, dong cua, huong cua
hieu va » lieu va, hieu qua
doi cua » dai cua, hoi cua
va cam » va cham, va cac, va cao
xuc va » tuc va, luc va, xac va
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: toc sach thu nang x hoi. hieu va cam ((xuc va) OR (duc va)) hanh ((doi cua) or (cong cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thu nang x hoi. hieu va cam ((xuc va) OR (duc va)) hanh ((doi cua) OR (cong cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach thu nang x hoi. hieu va cam ((xuc va) OR (duc va)) hanh ((doi cua) or (cong cua)) te".
• Adding a wildcard symbol may retrieve word variants: toc sach thu nang x hoi. hieu va cam ((xuc va) OR (duc va)) hanh ((doi cua) or (cong cua)) te*.