Perhaps you should try some spelling variations:
voi hoat » toi hoat, doi hoat, vo hoat
va hanh » van hanh, va thanh, va danh
va cham » va chat, va tham
tu sach » thu sach, su sach, te sach
nang co » nang cao, nang doc, nang noi
ly nang » ky nang, ly hang, ly vang
vu sach » vu bach, su sach, vu khach
hieu va » lieu va, hieu qua
co hoi » co hoc, co loi
soc va » hoc va, loc va, doc va
vi hoc » li hoc, va hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (vu sach)) ly nang co hoi. hieu va cham soc va hanh ((vi hoc) or (voi hoat)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (vu sach)) ly nang co hoi. hieu va cham soc va hanh ((vi hoc) OR (voi hoat)) viet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (vu sach)) ly nang co hoi. hieu va cham soc va hanh ((vi hoc) or (voi hoat)) viet*.