Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thu sach » tu sach, thuat sach, thuoc sach
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
ly hang » ly quang
ly nang » ky nang, ly vang, ly quang
ma hoi » mai hoi, xa hoi, ma hoa

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 ((ly nang) or (ly hang)) ma hoi. hieu va cac duc van thanh ((vai cua) or (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ly nang) OR (ly hang)) ma hoi. hieu va cac duc van thanh ((vai cua) OR (hai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ((ly nang) or (ly hang)) ma hoi. hieu va cac duc van thanh ((vai cua) or (hai cua)) tre*.