Perhaps you should try some spelling variations:
toan hanh » toan thanh, toan anh, tran hanh
thu sach » tu sach, thuat sach, thuoc sach
duc toan » duc tan, duc ton, duc hoan
tu cach » tu cac
cam duc » cam xuc, cao duc, pham duc
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang xa » lang xa, nang ma, mang xa
ve cam » ve cham, ve cac, va cam
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: ((tu cach) or (thu sach)) ky ((nang xa) OR (nang x)) hoi. hieu ve cam duc toan hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (thu sach)) ky ((nang xa) OR (nang x)) hoi. hieu ve cam duc toan hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (thu sach)) ky ((nang xa) OR (nang x)) hoi. hieu ve cam duc toan hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (thu sach)) ky ((nang xa) OR (nang x)) hoi. hieu ve cam duc toan hanh vi cua tre*.