Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
cu tren » dua tren
hang di » hang doi, hang vi, hang dien
va hang » van hang, va nang, va lang
nam duc » nam duoc, pham duc, nam thuc
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
tu tren » tu truyen, tu tieng, tu trong

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

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