Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cam truc » cau truc, nam truc, lam truoc
hieu van » hieu va, thien van, lieu va
te sach » toc sach
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
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: ((te sach) or (hoc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu van cam truc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (hoc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu van cam truc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (hoc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu van cam truc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (hoc sach)) ky ((nang xa) OR (nang ma)) hoi. hieu van cam truc va hanh vi cua tre*.