Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
vien cac » vien bach, vien dai, vien da
hanh vai » hanh vi, hanh va, hanh tai
vai cau » va cau, van cau, vai cac
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
lang xa » lang ha, dang xay, lang van
ty lang » tay lang, ty xang, ty hang
ve cac » va cac
xuc va » tuc va, luc va, xac va

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

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