Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
dau tren » dau tien, dat tren, dau tieng
mai hoi » mai khoi, lai hoi, mai doi
dai hoi » dai hoc, dai hai, dai moi
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cau luc » cau truc, cau phuc
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
ve cau » ke cau, va cau, ve cac
luc va » duc va, tuc va, loc va
vi dau » vi dai, va dau, bi dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky nang ((xa hoi) or (((mai hoi) OR (dai hoi)))). hieu ve cau luc va danh vi dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky nang ((xa hoi) OR (((mai hoi) OR (dai hoi)))). hieu ve cau luc va danh vi dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky nang ((xa hoi) or (((mai hoi) OR (dai hoi)))). hieu ve cau luc va danh vi dau tren".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang ((xa hoi) or (((mai hoi) OR (dai hoi)))). hieu ve cau luc va danh vi dau tren*.