Perhaps you should try some spelling variations:
thuat tac » thuat tach, thuat tao, thuat tai
nam truoc » nam thuoc, lam truoc, nam truc
va thanh » gia thanh, ban thanh, le thanh
hoc viet » hoc hien
qua nam » quan nam, cua nam, quang nam
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
va tinh » may tinh
va hanh » van hanh, va danh, ban hanh
tac ky » tac ke, cac ky, tap ky
vi hoc » li hoc, va hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat tac ky lang xa hoi. hieu qua nam truoc ((va hanh) or (((va thanh) OR (va tinh)))) vi hoc viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat tac ky lang xa hoi. hieu qua nam truoc ((va hanh) OR (((va thanh) OR (va tinh)))) vi hoc viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat tac ky lang xa hoi. hieu qua nam truoc ((va hanh) or (((va thanh) OR (va tinh)))) vi hoc viet".
• Adding a wildcard symbol may retrieve word variants: thuat tac ky lang xa hoi. hieu qua nam truoc ((va hanh) or (((va thanh) OR (va tinh)))) vi hoc viet*.