Perhaps you should try some spelling variations:
trinh ket » tinh ket, trinh ke, trinh kiem
toc sach » hoc sach, doc sach, thuoc sach
va trinh » van trinh, va tinh, lap trinh
sach ty » sach y, sach tu, sach thu
ty tang » tay tang, ty xang, ty hang
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
qua tre » cua tre, quan tren, quan tri
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ty tang ma hoi. ((hieu ve) or (lieu va)) cac duc va trinh ket qua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty tang ma hoi. ((hieu ve) OR (lieu va)) cac duc va trinh ket qua tre*.