Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
dinh va » dinh van, dinh ve, tinh va
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
va cau » van cau, va cac, va dau

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