Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
lang man » lang van, lang ban, lang mai
hanh vai » hanh vi, hanh tai, hanh van
su sach » so sach, vu sach
hanh va » hang va, hanh vi
cuu tre » cua tre, cau tren, cau treo
sach ky » sac ky, sach y, sach ty
man hoi » man hoai, dan hoi, van hoi
ky lang » ky nang, ky dang, ky tang
ve cac » va cac

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

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