Perhaps you should try some spelling variations:
thanh vinh » thanh binh, thanh tinh, than kinh
hieu van » hieu va, thien van, lieu va
vinh cuu » dinh cuu, sinh cua, dinh cu
van lam » van nam
cuu tre » cua tre, cau tren, cau treo
sach ky » sac ky, sach ty, sach kem
tuc va » thuc va, truc va, duc va
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: su ((sach ky) OR (sach y)) nang x hoi. hieu van lam ((tuc va) or (tuc xa)) thanh vinh cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) nang x hoi. hieu van lam ((tuc va) OR (tuc xa)) thanh vinh cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach y)) nang x hoi. hieu van lam ((tuc va) or (tuc xa)) thanh vinh cuu tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sach y)) nang x hoi. hieu van lam ((tuc va) or (tuc xa)) thanh vinh cuu tre*.