Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
toc sach » doc sach, thuoc sach, nuoc sach
hieu va » lieu va, hieu qua
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
cam tuc » cam xuc, cam tu, nam thuc
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, tuc xa
va cua » va chua, via cua, ca 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 sach) or (hoc sach))) or (toc sach)) ky nang ma hoi. hieu va cam tuc va hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (hoc sach))) OR (toc sach)) ky nang ma hoi. hieu va cam tuc va hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) or (hoc sach))) or (toc sach)) ky nang ma hoi. hieu va cam tuc va hanh va cua tre*.