Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ban hang » ngan hang
ty hang » ly hang, ty xang, thi hang
cho hoc » co hoc, khoa hoc
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
duc ban » duc tan, duc van, dua ban
ty nang » ty xang, ly nang, ty nong
hang di » hang doi, hang vi, hang dien
cua cau » cua cac, cua chu, cua cay
ve cac » va cac, vien cac
di cua » dai cua, doi cua, de 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 ((((ty nang) OR (ky nang))) or (ty hang)) cho hoc. hieu ve cac duc ban hang di cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((((ty nang) OR (ky nang))) OR (ty hang)) cho hoc. hieu ve cac duc ban hang di cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((((ty nang) OR (ky nang))) or (ty hang)) cho hoc. hieu ve cac duc ban hang di cua cau*".