Perhaps you should try some spelling variations:
thach duc » thach thuc, thinh duc
than duc » tran duc, phan duc, than doc
hanh vai » hanh va, hanh tai, hanh van
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
sach vu » sach va, sach tu, sach uu
cao hoi » cau hoi, co hoi, cao hoc
vu nang » vuc nang, va nang, vu dang

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

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