Perhaps you should try some spelling variations:
nhanh hai » nhanh thai, thanh hai, nhanh ha
hieu van » hieu va, thien van, lieu va
hanh hai » thanh hai, hang hai, hanh tai
tu sach » thu sach, su sach, te sach
truc va » thuc va, thuc vat, trung va
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
luc va » duc va, tuc va, loc va

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 ty nang xa hoi. hieu van nam ((luc va) or (truc va)) ((hanh hai) OR (nhanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang xa hoi. hieu van nam ((luc va) OR (truc va)) ((hanh hai) OR (nhanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang xa hoi. hieu van nam ((luc va) or (truc va)) ((hanh hai) OR (nhanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. hieu van nam ((luc va) or (truc va)) ((hanh hai) OR (nhanh hai)) cua tre*.