Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
toc sach » hoc sach, doc sach, thuoc sach
ban hanh » ban hang
nang mai » nang ma, nang tai, lang mai
chat hoc » chat hoa, chat thom, cho hoc
hieu va » lieu va, hieu qua
hanh ve » hanh vi, hanh va, hanh kem
hoc ban » hoc bang, hoc dan, hoc bai
hieu ve » hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ve su » va su

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

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