Perhaps you should try some spelling variations:
vien cac » vien bach, vien da, gian cac
vien dai » hien dai
hanh tai » thanh tai, hang tai, han tai
so sach » so sanh, bo sach, co sach
xuc van » duc van, luc van, vuc van
cuc tre » duc tre, cua tre, cuu tre
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang o hai. hieu ((vien cac) or (vien dai)) ((xuc van) or (duc tan)) hanh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang o hai. hieu ((vien cac) OR (vien dai)) ((xuc van) OR (duc tan)) hanh tai cuc tre.
• Adding a wildcard symbol may retrieve word variants: so sach y nang o hai. hieu ((vien cac) or (vien dai)) ((xuc van) or (duc tan)) hanh tai cuc tre*.