Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
sang lap » sang tao, sang ma, sang tai
vien cac » vien bach, vien dai, vien da
cac luc » cau luc, coc luc, cac nuoc
sach ky » sach y, sach ty, sach kem
lap lai » lap tai, lay lai, lam lai
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va
va dan » ca dan, va dao, va dau
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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: su ((sach ky) OR (sac ky)) sang lap lai. hieu vien cac luc va dan ((vi cua) OR (di cua)) te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sac ky)) sang lap lai. hieu vien cac luc va dan ((vi cua) OR (di cua)) te~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sac ky)) sang lap lai. hieu vien cac luc va dan ((vi cua) OR (di cua)) te*.