Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
thai cua » than cua, tai cuc, tri cua
so sach » so sanh, bo sach, co sach
duc van » duc va, duc tan, duc manh
luc van » luoc van, luu van, luc va
hieu ve » hieu va, hieu van
ly nang » ky nang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
y nang » ky nang, v nang, may nang
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) OR (ly nang)) o hai. hieu ve cam ((luc van) or (duc van)) hanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((y nang) OR (ly nang)) o hai. hieu ve cam ((luc van) OR (duc van)) hanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((y nang) OR (ly nang)) o hai. hieu ve cam ((luc van) or (duc van)) hanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ((y nang) OR (ly nang)) o hai. hieu ve cam ((luc van) or (duc van)) hanh thai cua tre*.