Perhaps you should try some spelling variations:
van trinh » van thinh, van tinh, dan trinh
trinh boi » trinh hoi, trinh bong, trinh do
hieu van » hieu va, thien van, lieu va
van chao » van chat, van hao, van cho
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
nang ma » tang ma, sang ma, nang cao
boi cua » hoi cua, doi cua, moi cua
cua tre » cua te, cuu tre, cua triet
xu van » tu van, vu van, su van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky ((lang xa) or (nang ma)) hoi. hieu van chao xu van trinh boi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((lang xa) OR (nang ma)) hoi. hieu van chao xu van trinh boi cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ky ((lang xa) or (nang ma)) hoi. hieu van chao xu van trinh boi cua tre*.