Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
sach ky » sac ky, sach y, sach ty
cu tren » tu tren, dua tren
dai hoi » dai hoc, dai hai, dai moi
tai hoi » tai khoi, tai hai, tai hoe
luc va » duc va, tuc va
loc va » hoc va
va cam » va cham, va cac, va cao
vi cu » vi su, vi xu, vi du

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang ((tai hoi) or (dai hoi)). lieu va cam ((luc va) OR (loc va)) hanh vi cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((tai hoi) OR (dai hoi)). lieu va cam ((luc va) OR (loc va)) hanh vi cu tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((tai hoi) or (dai hoi)). lieu va cam ((luc va) OR (loc va)) hanh vi cu tren*".