Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
ve cai » va cai, ve cac, ve tai
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((nang xa) or (nang ma)) hoi. hieu ((ve cai) or (va cac)) luc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (nang ma)) hoi. hieu ((ve cai) OR (va cac)) luc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (nang ma)) hoi. hieu ((ve cai) or (va cac)) luc va hanh vi cua tre*.