Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
van hanh » van thanh, ban hanh, van anh
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va hanh » va thanh, va danh, ban hanh
v lang » va lang, o lang, _ lang
di cua » dai cua, doi cua, de cua
cua te » cua tu

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) OR (doc sach)) v lang xa hoi. hieu va cac duc ((va hanh) or (van hanh)) di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) v lang xa hoi. hieu va cac duc ((va hanh) OR (van hanh)) di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) v lang xa hoi. hieu va cac duc ((va hanh) or (van hanh)) di cua te".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) v lang xa hoi. hieu va cac duc ((va hanh) or (van hanh)) di cua te*.