Perhaps you should try some spelling variations:
hieu thien » hieu hien, chieu chien, dieu khien
toc sach » hoc sach, doc sach, thuoc sach
tu tieng » luc tieng, tu tuong, tu trong
cac ban » cac van, can ban, cac bai
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
su tien » su kien, su hien, dau tien
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y nang x hoi. hieu thien ((cac ban) OR (cac dan)) va danh vi ((su tien) or (tu tieng))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang x hoi. hieu thien ((cac ban) OR (cac dan)) va danh vi ((su tien) OR (tu tieng)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang x hoi. hieu thien ((cac ban) OR (cac dan)) va danh vi ((su tien) or (tu tieng))".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang x hoi. hieu thien ((cac ban) OR (cac dan)) va danh vi ((su tien) or (tu tieng))*.