Perhaps you should try some spelling variations:
trinh toan » tinh toan, thanh toan, trinh han
hien hanh » dieu hanh
hieu hien » bieu hien, dieu hien, chieu chien
trinh van » trinh han, trinh quan, dinh van
hanh xuc » hanh xu, hanh phuc, hanh duoc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cho tre » cho thue, khoe tre
xuc va » duc va, tuc va, luc va
x hoi » xa hoi, o hoi, 5 hoi

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 ky nang ((x hoi) OR (x ho)). hieu hien hanh xuc va ((trinh van) or (trinh toan)) cho tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (x ho)). hieu hien hanh xuc va ((trinh van) OR (trinh toan)) cho tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) OR (x ho)). hieu hien hanh xuc va ((trinh van) or (trinh toan)) cho tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) OR (x ho)). hieu hien hanh xuc va ((trinh van) or (trinh toan)) cho tre*.