Perhaps you should try some spelling variations:
thanh luc » thanh luu, than luc, nhan luc
hoang hai » hoang thi, hoang van
van thanh » ban thanh, van tuan
hang hai » hang tai, thanh hai, hang va
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van 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 ((y nang) OR (v nang)) ma hoa. hieu van thanh luc va ((hang hai) or (hoang hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (v nang)) ma hoa. hieu van thanh luc va ((hang hai) OR (hoang hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (v nang)) ma hoa. hieu van thanh luc va ((hang hai) or (hoang hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) OR (v nang)) ma hoa. hieu van thanh luc va ((hang hai) or (hoang hai)) cua tre*.