Perhaps you should try some spelling variations:
vien cao » vien cac, vien da, vien va
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
vien cay » vien cac, vien xay, vien can
vien dai » hien dai
vu sach » vu bach, su sach, vu khach
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
vi cua » vai cua, di cua

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