Perhaps you should try some spelling variations:
dang xay » dang van, van xay
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hang di » hang doi, hang vi, hang dien
va hang » van hang, va nang, va lang
nam duc » nam duoc, pham duc, nam thuc
lang xa » lang ha, lang van
cu tren » tu tren, dua tren
di cu » di cau, di cua, di du

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