Perhaps you should try some spelling variations:
dinh dai » dinh dat, sinh dai, dinh dao
toc sach » hoc sach, doc sach, thuoc sach
tu sach » thu sach, su sach, te sach
va dinh » van dinh, va kinh, va tinh
cau luc » cau truc, cau phuc
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
ve cau » ke cau, va cau, ve cac
luc va » duc va, tuc va, loc va
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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 tang xa hoi. hieu ve cau luc va dinh dai ((cua tu) OR (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ky tang xa hoi. hieu ve cau luc va dinh dai ((cua tu) OR (cua su)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) ky tang xa hoi. hieu ve cau luc va dinh dai ((cua tu) OR (cua su))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky tang xa hoi. hieu ve cau luc va dinh dai ((cua tu) OR (cua su))*.