Perhaps you should try some spelling variations:
thien van » thi van
trinh voi » trinh hoi, trinh vi, trinh boi
may trinh » may tinh, lap trinh, quy trinh
truc may » tren may, truc va
lam truc » lam truoc, nam truc, lam thuoc
hieu van » hieu va, lieu va
tu sach » thu sach, su sach, te sach
voi cua » hoi cua, doi cua, moi cua
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet

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 ty nang xa hoi. ((((hieu ve) OR (hieu van))) or (thien van)) lam truc may trinh voi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang xa hoi. ((((hieu ve) OR (hieu van))) OR (thien van)) lam truc may trinh voi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang xa hoi. ((((hieu ve) OR (hieu van))) or (thien van)) lam truc may trinh voi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. ((((hieu ve) OR (hieu van))) or (thien van)) lam truc may trinh voi cua tre*.