Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hang vai » hang va, hang tai, hang hai
ban hang » ngan hang
cau tren » cu tren, dau tren, ca tren
cau dua » cau qua, cau cua, ca dua
van cau » van dau, van hau, van chat
dua ban » dia ban, cua ban, qua ban
vai cau » va cau, vai cac, lai chau
me hoi » le hoi
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, va hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y nang ((((ma hoi) OR (me hoi))) or (ma hoa)). hieu van cau dua ban hang vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang ((((ma hoi) OR (me hoi))) OR (ma hoa)). hieu van cau dua ban hang vai cau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang ((((ma hoi) OR (me hoi))) or (ma hoa)). hieu van cau dua ban hang vai cau tren*".