Perhaps you should try some spelling variations:
hieu luc » hieu luat, hieu qua
nhat luc » nhan luc, nhat nuoc, nhat cua
va tinh » may tinh
su sach » so sach, vu sach
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
te sach » toc sach
luc va » duc va, tuc va, loc va
di cua » dai cua, doi cua, do cua
de cua » le cua, te cua, dieu cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (te sach)) ky lang xa hoi. hieu luc nhat luc va tinh ((di cua) OR (de cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (te sach)) ky lang xa hoi. hieu luc nhat luc va tinh ((di cua) OR (de cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (te sach)) ky lang xa hoi. hieu luc nhat luc va tinh ((di cua) OR (de cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (te sach)) ky lang xa hoi. hieu luc nhat luc va tinh ((di cua) OR (de cua)) tre*.