Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
dat thanh » dao thanh, dat khanh, dang thanh
vu khach » vu khanh, vu khac, vay khach
day manh » van manh, duc manh, ha manh
vu sach » vu bach, su sach
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
ly nang » ky nang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet
de cua » le cua, te cua, dieu 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 sach) OR (vu khach)) ly nang x hoi. hieu ve cham thuc ((day manh) or (dat thanh)) de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) ly nang x hoi. hieu ve cham thuc ((day manh) OR (dat thanh)) de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) OR (vu khach)) ly nang x hoi. hieu ve cham thuc ((day manh) or (dat thanh)) de cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) OR (vu khach)) ly nang x hoi. hieu ve cham thuc ((day manh) or (dat thanh)) de cua tre*.