Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
va cua » va chua, via cua, ca cua
dan va » doan va, dan ca, ban va
va dan » ca dan, va dao, va dau
ve cam » ve cham, ve cac, va cam
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach tu) OR (sach ty)) nang x hoi. hieu ((ve cam) or (vien cac)) duc va dan va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach tu) OR (sach ty)) nang x hoi. hieu ((ve cam) OR (vien cac)) duc va dan va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach tu) OR (sach ty)) nang x hoi. hieu ((ve cam) or (vien cac)) duc va dan va cua te".
• Adding a wildcard symbol may retrieve word variants: te ((sach tu) OR (sach ty)) nang x hoi. hieu ((ve cam) or (vien cac)) duc va dan va cua te*.