Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
xa hanh » xa thanh, xa khanh, va hanh
cao suc » cao su, cao duc
cao tuc » dao tuc, cao duc, cao toc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
tu lang » cu lang, tu lanh, xu lang
vi cua » vai cua, di cua

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 (hoc sach)) tu lang xa hoi. hieu va ((cao tuc) OR (cao suc)) xa hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) tu lang xa hoi. hieu va ((cao tuc) OR (cao suc)) xa hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (hoc sach)) tu lang xa hoi. hieu va ((cao tuc) OR (cao suc)) xa hanh vi cua tre*".