Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hieu ve » hieu va, hieu van
va kinh » va tinh, qua kinh
va dinh » van dinh, va tinh, vu dinh
cam duc » cam xuc, cao duc, pham duc
hoc sac » hoc sach, hoc cac, hoc mac
ky dang » ky nang, ky danh
tay ho » tay co, tay o, tay khao
sac ky » cac ky, sai ky
ve cam » ve cham, ve cac, va cam
ve su » va su

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sac ky dang ((xa hoi) or (tay ho)). hieu ve cam duc ((va dinh) or (va kinh)) ve su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sac ky dang ((xa hoi) OR (tay ho)). hieu ve cam duc ((va dinh) OR (va kinh)) ve su triet.
• Adding a wildcard symbol may retrieve word variants: hoc sac ky dang ((xa hoi) or (tay ho)). hieu ve cam duc ((va dinh) or (va kinh)) ve su triet*.