Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
toc sach » hoc sach, doc sach, thuoc sach
tinh di » tinh doi, trinh di, tinh da
va tinh » may tinh
cac dac » cac dan, cac dai, cac bac
hieu va » lieu va, hieu qua
lang o » lang _, tang o, lang son
xang o » tang o, dang o
dac va » duc va, day va, dat va
di su » doi su, ki su, da su

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) y ((xang o) OR (lang o)) hoi. hieu va cac dac va tinh di su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) y ((xang o) OR (lang o)) hoi. hieu va cac dac va tinh di su triet~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) y ((xang o) OR (lang o)) hoi. hieu va cac dac va tinh di su triet*.