Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
dinh tai » dinh toai, dinh tri, dinh thi
cau tren » cu tren, dau tren, ca tren
dang xa » dang xay, lang xa, dang ha
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dinh vi » dinh ve, dinh viet, dinh tri
ve cam » ve cham, va cam, ve cai
luc va » duc va, tuc va, loc va
ve cac » va cac, vien cac

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

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