Perhaps you should try some spelling variations:
hanh via » hanh vi, hanh va, anh va
su sach » so sach, vu sach
via cua » gia cua, gian cua, giau cua
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
bao bo » bac bo, ban bo, bao bi
nao bo » nam bo

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang ma) OR (sang ma)) hoi. hieu va ((bao bo) or (nao bo)) va hanh via cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang ma) OR (sang ma)) hoi. hieu va ((bao bo) OR (nao bo)) va hanh via cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang ma) OR (sang ma)) hoi. hieu va ((bao bo) or (nao bo)) va hanh via cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang ma) OR (sang ma)) hoi. hieu va ((bao bo) or (nao bo)) va hanh via cua tre*.