Perhaps you should try some spelling variations:
dich hoc » sinh hoc, hinh hoc, tinh hoc
tay thai » lay thai, toc thai, y thai
cua tre » cua te, cuu tre, cua triet
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
va dich » van dich
hieu va » lieu va, hieu qua
tay hoi » tay ho, tao hoi
sac ky » cac ky, sai ky
ky anh » ky danh, ly anh, ty anh
vi cua » vai cua, di cua
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky anh ((tay hoi) OR (tay thai)). hieu va dich hoc ((va hanh) or (va danh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky anh ((tay hoi) OR (tay thai)). hieu va dich hoc ((va hanh) OR (va danh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky anh ((tay hoi) OR (tay thai)). hieu va dich hoc ((va hanh) or (va danh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky anh ((tay hoi) OR (tay thai)). hieu va dich hoc ((va hanh) or (va danh)) vi cua tre*.