Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh tai, hanh van
hieu van » thien van, lieu va, hieu ve
su sach » so sach, vu sach
dau xuc » dau xac, dau xua, dau nuoc
hanh va » hang va, hanh vi
xuc van » duc van, luc van, xuc ban
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa

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