Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van nhan » van phan, van thanh, danh nhan
va thanh » gia thanh, ban thanh, va tinh
nhan duc » nhan duoc, nhan luc, phan duc
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
tu sach » thu sach, su sach, te sach
vu nang » vuc nang, va nang, vu dang
v nang » va nang, van nang, voi nang

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

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