Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
nang dai » nang dau, nang tai, lang dai
sach ty » sach y, sach tu, sach thu
tai dau » tac dau, tai du, thi dau
han tai » hang tai, nhan tai, van tai
te sach » toc sach
dai hoi » dai hoc, dai hai, dai moi
ty nang » ky nang, ty xang, ty hang
ve cam » ve cham, ve cac, ve cai
va cam » va cham, va cac, va cao
xuc va » tuc va, luc va, xac va

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 dai hoi. hieu ((ve cam) OR (va cam)) ((xuc va) or (duc va)) han tai dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang dai hoi. hieu ((ve cam) OR (va cam)) ((xuc va) OR (duc va)) han tai dau tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang dai hoi. hieu ((ve cam) OR (va cam)) ((xuc va) or (duc va)) han tai dau tren*".