Perhaps you should try some spelling variations:
ngon thanh » ngoc thanh, ngo thanh, nguoi thanh
thanh vai » thanh hai, thanh van, thanh tai
duc ngon » duc ngoc, dung ngon, duoi ngon
thu hang » thi hang, thuc hanh, thu huong
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
vai cua » dai cua, hai cua, lai cua
hieu ve » hieu va
cam duc » cam xuc, cao duc, pham duc
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: so sach ((thu hang) or (ty xang)) xa hoi. ((hieu ve) OR (hieu van)) cam duc ngon thanh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((thu hang) OR (ty xang)) xa hoi. ((hieu ve) OR (hieu van)) cam duc ngon thanh vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((thu hang) or (ty xang)) xa hoi. ((hieu ve) OR (hieu van)) cam duc ngon thanh vai cua te".
• Adding a wildcard symbol may retrieve word variants: so sach ((thu hang) or (ty xang)) xa hoi. ((hieu ve) OR (hieu van)) cam duc ngon thanh vai cua te*.