Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
te sach » toc sach
tai cua » thai cua, tai cuc, tri cua
luu van » cuu van, luan van, luu hanh
luc van » luoc van, duc van, luc va
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
nang ho » nang hoc, nang co, tang ho
ty nang » ky nang, ty xang, ty hang
va cam » va cham, va cac, va cao
ve cam » ve cham, ve cac, ve cai
ho hoi » hoc hoi, hoa hoi, hoi hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty nang ho hoi. hieu ((ve cam) OR (va cam)) ((luc van) or (luu van)) hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang ho hoi. hieu ((ve cam) OR (va cam)) ((luc van) OR (luu van)) hanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang ho hoi. hieu ((ve cam) OR (va cam)) ((luc van) or (luu van)) hanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang ho hoi. hieu ((ve cam) OR (va cam)) ((luc van) or (luu van)) hanh tai cua tre*.