Perhaps you should try some spelling variations:
nhat luc » nhan luc, nhat nuoc, nhat cua
trinh di » trinh do, trinh dien, trinh dinh
hieu luc » hieu luat, hieu qua
tinh di » tinh doi, tinh da, tin di
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
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va

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) OR (trinh di)) 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) OR (trinh di)) 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) OR (trinh di)) 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) OR (trinh di)) cua tre*.