Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sang tay » sang tao, sang tai, sang tac
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cham luc » cham soc, nhan luc, cham cuu
ban phan » van phan, ban than, ban nhan
dua tren » dung tren
sach ty » sach y, sach tu, sach thu
ty sang » ty xang, ty hang, duy sang
tay hoi » tay ho, tao hoi, tay thai
cua te » cua tu

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 sang tay hoi. hieu van cham luc ((ban phan) or (ban phap)) lap ((dua tren) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty sang tay hoi. hieu van cham luc ((ban phan) OR (ban phap)) lap ((dua tren) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: toc sach ty sang tay hoi. hieu van cham luc ((ban phan) or (ban phap)) lap ((dua tren) or (cua te))*.