Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
tang mam » dang mam, mang mam, tang dam
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
vu cham » va cham, vu kham, tu cham
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
tang ma » mang may, tang van
xuc va » duc va, tuc va, luc va
va cua » va chua, via cua, ca cua
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: hoc sach ky ((tang ma) or (tang mam)) hoi. hieu ((ve cam) or (vu cham)) xuc va hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky ((tang ma) OR (tang mam)) hoi. hieu ((ve cam) OR (vu cham)) xuc va hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach ky ((tang ma) or (tang mam)) hoi. hieu ((ve cam) or (vu cham)) xuc va hanh va cua tre*.