Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
nang cho » nang chon, ngang cho, nang cao
hieu van » hieu va, thien van, lieu va
doc sach » hoc sach, nuoc sach, dac sac
ty nang » ky nang, ty xang, ty hang
cho hoc » co hoc, khoa hoc
van cac » van hac, van cau, van bac
dac van » cac van, dao van, duc van
dam van » dao van, nam van, pham van
cua cau » cua cac, cua chu, cua cay
anh vi » hanh vi, anh va, anh ve
vi cua » vai cua, di cua

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) OR (doc sach)) ty nang cho hoc. hieu van cac ((dac van) or (dam van)) anh vi cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ty nang cho hoc. hieu van cac ((dac van) OR (dam van)) anh vi cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ty nang cho hoc. hieu van cac ((dac van) or (dam van)) anh vi cua cau*".