Perhaps you should try some spelling variations:
tao nano » tao nganh, cao nang, tao cao
toan cao » toan ban, toan tap
van hanh » van thanh, ban hanh, van ban
su sach » so sach, vu sach
van anh » van thanh, tuan anh, van minh
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, chat xuc
bac hoc » bai hoc, bac ho
cua tre » cua te, cuu tre, cua triet
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: su sach ((tao nano) or (toan cao)) bac hoc. hieu va cac xuc ((van hanh) OR (van anh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((tao nano) OR (toan cao)) bac hoc. hieu va cac xuc ((van hanh) OR (van anh)) va cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((tao nano) or (toan cao)) bac hoc. hieu va cac xuc ((van hanh) OR (van anh)) va cua tre*".