Perhaps you should try some spelling variations:
vien cay » vien xay, vien can, vien may
vien cac » vien bach, vien dai, vien da
vien cao » vien dai, vien da, vien va
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
bach ty » sach ty, xach tay, bach thu
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu bach ty nang x hoi. hieu ((((vien cay) OR (vien cac))) or (vien cao)) thuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu bach ty nang x hoi. hieu ((((vien cay) OR (vien cac))) OR (vien cao)) thuc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu bach ty nang x hoi. hieu ((((vien cay) OR (vien cac))) or (vien cao)) thuc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu bach ty nang x hoi. hieu ((((vien cay) OR (vien cac))) or (vien cao)) thuc van hanh vi cua tre*.