Perhaps you should try some spelling variations:
day nhanh » day thanh, duy nhanh, dac nhan
nham thuc » nhan thuc, nam thuc, nham thu
day hanh » day thanh, dao hanh, day manh
duc manh » suc manh, duc anh, duc minh
hieu van » hieu va, thien van, lieu va
van nham » van nam, van nhan, van tham
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
nang o » nang co, nang ho, nang ro
di cuu » di cau, di cua, dinh cuu
o hoi » co hoi, o hoc, o hai

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 ky nang o hoi. hieu van nham thuc ((((day hanh) or (duc manh))) or (day nhanh)) di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang o hoi. hieu van nham thuc ((((day hanh) OR (duc manh))) OR (day nhanh)) di cuu tre.
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang o hoi. hieu van nham thuc ((((day hanh) or (duc manh))) or (day nhanh)) di cuu tre*.