Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
cau tren » cu tren, dau tren, ca tren
hoc sach » hoc sinh, hoc cac, hoc anh
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cao suc » cao su
cao duc » dao duc, giao duc, tao duoc
v lang » va lang, o lang, _ lang
va dan » ca dan, va dao, va dau
dan di » danh di, dan da, dan de
di cau » da cau, diem cau

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

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