Perhaps you should try some spelling variations:
doc sach » toc sach, nuoc sach, dac sac
hoc sach » hoc sinh, hoc cac, hoc anh
dan giao » dang giao, dan gian, dan giai
hieu van » hieu va, thien van, lieu va
giao su » giao duc
cac xuc » cam xuc, cac nuoc, chat xuc
van cac » van hac, van cau, van bac
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
su tien » su kien, su hien, tu tieng
xuc va » duc va, tuc va, luc va
va dan » ca dan, va dao, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc sach) or (hoc sach)) ((ty nang) or (ty hang)) xa hoi. hieu van cac xuc va dan giao su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (hoc sach)) ((ty nang) OR (ty hang)) xa hoi. hieu van cac xuc va dan giao su tien.
• Adding a wildcard symbol may retrieve word variants: ((doc sach) or (hoc sach)) ((ty nang) or (ty hang)) xa hoi. hieu van cac xuc va dan giao su tien*.