Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
van thanh » ban thanh, van tuan
hoa vang » hoa lang, hoa van, hoa nang
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
cao duc » dao duc, cao suc, giao duc
vai cua » dai cua, hai cua, lai cua
cam duc » cam xuc, pham duc, nam duoc
lo vang » lo van, ly vang
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ((lo vang) OR (hoa vang)) xa hoi. hieu van ((cam duc) or (cao duc)) van thanh vai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((lo vang) OR (hoa vang)) xa hoi. hieu van ((cam duc) OR (cao duc)) van thanh vai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ((lo vang) OR (hoa vang)) xa hoi. hieu van ((cam duc) or (cao duc)) van thanh vai cua tu".
• Adding a wildcard symbol may retrieve word variants: vu sach ((lo vang) OR (hoa vang)) xa hoi. hieu van ((cam duc) or (cao duc)) van thanh vai cua tu*.