Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
truc van » truc va, thuc van, truc ban
hang vi » hang va, hanh vi, hang di
sach tu » sach thu, cach tu, sach ty
cua tre » cua te, cuu tre, cua triet
tuc van » thuc van, duc van, tuc dan
va cham » va chat, va tham
hieu va » lieu va, hieu qua
tu nang » tru nang, tu nong, tu nano
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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 tu nang x hoi. hieu va cham ((((tuc van) OR (tuc va))) or (truc van)) hang vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tu nang x hoi. hieu va cham ((((tuc van) OR (tuc va))) OR (truc van)) hang vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tu nang x hoi. hieu va cham ((((tuc van) OR (tuc va))) or (truc van)) hang vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach tu nang x hoi. hieu va cham ((((tuc van) OR (tuc va))) or (truc van)) hang vi cua tre*.