Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tao nano » tao nganh, tao cao, tao nhan
cao nang » cao dang, cam nang, cao tang
vu sach » vu bach, su sach, vu khach
cua tre » cua te, cua triet, dua tren
hanh va » hang va, hanh vi
qua cam » qua cham, qua cac, qua ca
cuu tre » cau tren, cau treo
xuc van » duc van, luc van, vuc van

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ((tao nano) OR (cao nang)) cau hoi. hieu qua cam xuc van hanh va ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((tao nano) OR (cao nang)) cau hoi. hieu qua cam xuc van hanh va ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ((tao nano) OR (cao nang)) cau hoi. hieu qua cam xuc van hanh va ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: vu sach ((tao nano) OR (cao nang)) cau hoi. hieu qua cam xuc van hanh va ((cua tre) or (cuu tre))*.