Perhaps you should try some spelling variations:
dinh vai » dinh van, dinh vi, dinh va
cau tren » cu tren, dau tren, ca tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu ve » hieu va, hieu van
cam hoc » cao hoc, cam hoa, cac hoc
va dinh » van dinh, va kinh, va tinh
vai cau » va cau, van cau, vai cac
am hoc » ad hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky dang xa hoi. hieu ve ((cam hoc) or (am hoc)) va dinh vai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang xa hoi. hieu ve ((cam hoc) OR (am hoc)) va dinh vai cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang xa hoi. hieu ve ((cam hoc) or (am hoc)) va dinh vai cau tren*.