Perhaps you should try some spelling variations:
tang dan » tang van, tung dan, tang luan
ky tang » ky nang, ky dang, kho tang
dan hoc » van hoc, dan toc, dai hoc
hieu vu » hieu ve, hieu su, dieu vu
hieu va » lieu va, hieu qua
tu sac » tu sach, tu cac, tu san
vu van » tu van
vi cua » vai cua, di cua
sac ky » cac ky, sai ky
xu van » tu van, su van
cua te » cua tu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky tang dan hoc. ((hieu vu) OR (hieu va)) chao ((xu van) OR (vu van)) hanh vi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky tang dan hoc. ((hieu vu) OR (hieu va)) chao ((xu van) or (vu van)) hanh vi cua te~".
• Adding a wildcard symbol may retrieve word variants: tu sac ky tang dan hoc. ((hieu vu) OR (hieu va)) chao ((xu van) or (vu van)) hanh vi cua te*.