Perhaps you should try some spelling variations:
khanh sinh » khang sinh, khanh linh, khanh vinh
sinh cua » manh cua, dinh cuu, sinh va
thi hang » thi hanh, thi nang, thi hong
va khanh » van khanh, va thanh, vu khanh
tu sach » thu sach, te sach, tu cach
nam mua » nam qua, nam xua, nam luat
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
su sach » so sach, vu sach
hang x » nang x, hoang xa, chang xu
x hoi » xa hoi, o hoi, x ho

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 (su sach)) thi hang x hoi. hieu va ((nam cua) or (nam mua)) va khanh sinh cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) thi hang x hoi. hieu va ((nam cua) OR (nam mua)) va khanh sinh cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) thi hang x hoi. hieu va ((nam cua) or (nam mua)) va khanh sinh cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) thi hang x hoi. hieu va ((nam cua) or (nam mua)) va khanh sinh cua tre*.