Perhaps you should try some spelling variations:
thien van » thi van
sach tru » sach truc, sach thu, sach tu
tru nang » tra nang, tri nang, truc nano
dua tren » dung tren
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
cua tre » cuu tre, cua triet, cua thep
can ban » van ban, toan ban
cam can » cam chan, cap can, cam nang
van cam » van nam, van lam, van cau
nang xa » nang x, lang xa, nang ma
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach tru nang xa hoi. thien van cam can ban hanh vi ((((cua tre) OR (dua tren))) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tru nang xa hoi. thien van cam can ban hanh vi ((((cua tre) OR (dua tren))) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tru nang xa hoi. thien van cam can ban hanh vi ((((cua tre) OR (dua tren))) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach tru nang xa hoi. thien van cam can ban hanh vi ((((cua tre) OR (dua tren))) or (cua te))*.