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
sach ky » sac ky, sach y, sach ty
nang ho » nang hoc, nang co, tang ho
hieu ve » hieu va, hieu van
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ro, nang x
ve cam » ve cham, ve cac, va cam

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 ky ((nang o) OR (nang ho)) hai. hieu ve cam ((xuc van) or (duc van)) hanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((nang o) OR (nang ho)) hai. hieu ve cam ((xuc van) OR (duc van)) hanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((nang o) OR (nang ho)) hai. hieu ve cam ((xuc van) or (duc van)) hanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ky ((nang o) OR (nang ho)) hai. hieu ve cam ((xuc van) or (duc van)) hanh thai cua tre*.