Perhaps you should try some spelling variations:
hieu luc » hieu luat, hieu qua
vanh tri » van tri, vanh tai, thanh tri
tu sach » thu sach, su sach, te sach
vu sach » vu bach, su sach, vu khach
so sach » so sanh, bo sach, co sach
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
luc dao » duc dao, lua dao, luc cao
dao duc » giao duc, tao duoc
va vanh » va van, va danh, va hanh
cua te » cua tu

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 (((vu sach) or (so sach)))) ky lang xa hoi. hieu luc dao duc va vanh tri cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (((vu sach) OR (so sach)))) ky lang xa hoi. hieu luc dao duc va vanh tri cua te.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (((vu sach) or (so sach)))) ky lang xa hoi. hieu luc dao duc va vanh tri cua te*.