Perhaps you should try some spelling variations:
hanh vinh » thanh vinh, khanh vinh, hanh tinh
vinh cua » sinh cua, tinh cua, dinh cua
sach ky » sac ky, sach ty, sach kem
hieu su » hieu sau, tieu su, hieu so
xuc van » duc van, luc van, xuc ban
vuc van » duc van, luc van, thuc van
cua tre » cua te, cuu tre, cua triet
su cam » su nam, su cao, su can
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 ky) or (sach y)) nang x hoi. hieu su cam ((xuc van) OR (vuc van)) hanh vinh cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang x hoi. hieu su cam ((xuc van) OR (vuc van)) hanh vinh cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach y)) nang x hoi. hieu su cam ((xuc van) OR (vuc van)) hanh vinh cua tre*".