Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh dai » hanh tai, hanh dao, vanh dai
va triet » va thiet, va trien, ve triet
nang dau » hang dau, xang dau, nang du
dau hoi » cau hoi, dai hoi, dan hoi
ve cham » va cham, ve chat, vu cham
truc va » thuc va, thuc vat, trung va
va chat » van chat, va phat, cao chat
sach v » sach va, sach y, sach 2
xuc va » duc va, tuc va, luc va
v nang » va nang, vu nang, van nang
dai va » mai va

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach v nang dau hoi. hieu ((ve cham) or (va chat)) ((xuc va) or (truc va)) hanh dai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v nang dau hoi. hieu ((ve cham) OR (va chat)) ((xuc va) OR (truc va)) hanh dai va triet.
• Adding a wildcard symbol may retrieve word variants: toc sach v nang dau hoi. hieu ((ve cham) or (va chat)) ((xuc va) or (truc va)) hanh dai va triet*.