Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
vat cua » mat cua, bat cua, dat cua
cua tre » cua te, cuu tre, cua triet

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 tang xa hoi. hieu ((vo coc) or (vo co)) ((duc va) or (tuc xa)) trinh vat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky tang xa hoi. hieu ((vo coc) OR (vo co)) ((duc va) OR (tuc xa)) trinh vat cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky tang xa hoi. hieu ((vo coc) or (vo co)) ((duc va) or (tuc xa)) trinh vat cua tre*.