Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
toc sach » hoc sach, doc sach, thuoc sach
hieu van » thien van, lieu va, hieu ve
danh vai » danh sai, danh va, dang van
cau tren » cu tren, dau tren, ca tren
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
xuc va » duc va, tuc va, luc va

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 ky lang xa hoi. ((hieu van) OR (hieu va)) cam xuc va ((danh vai) or (doanh van)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. ((hieu van) OR (hieu va)) cam xuc va ((danh vai) OR (doanh van)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky lang xa hoi. ((hieu van) OR (hieu va)) cam xuc va ((danh vai) or (doanh van)) cau tren".
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. ((hieu van) OR (hieu va)) cam xuc va ((danh vai) or (doanh van)) cau tren*.