Perhaps you should try some spelling variations:
thien van » thi van
thu sach » tu sach, thuat sach, thuoc sach
hang vai » hang va, hang tai, hang hai
ban hang » ngan hang
vai cuu » vai cua
dua ban » dia ban, cua ban, qua ban
cay dua » chay dua, cay lua, ca dua
van cay » van cau, van bay, van ca
cuu tre » cua tre, cau tren, cau treo
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
ma hoi » mai hoi, xa hoi, me 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 ((ty nang) OR (ty hang)) ((ma hoi) or (ma hoa)). thien van cay dua ban hang vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty nang) OR (ty hang)) ((ma hoi) OR (ma hoa)). thien van cay dua ban hang vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ty nang) OR (ty hang)) ((ma hoi) or (ma hoa)). thien van cay dua ban hang vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty nang) OR (ty hang)) ((ma hoi) or (ma hoa)). thien van cay dua ban hang vai cuu tre*.