Perhaps you should try some spelling variations:
dieu cua » dieu tra
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
cham lo » cham o, cam lo, cham soc
ca chua » ca cua, sua chua
va danh » va dinh, va dan, va hanh
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
nang xa » nang x, lang xa, nang ma
tu nang » tru nang, tu nong, tu nano
lo va » lo van, lao va, ly va

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 (thu sach)) tu nang xa hoi. hieu vu cham lo va danh ((ca chua) or (dieu cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) tu nang xa hoi. hieu vu cham lo va danh ((ca chua) OR (dieu cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) tu nang xa hoi. hieu vu cham lo va danh ((ca chua) or (dieu cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) tu nang xa hoi. hieu vu cham lo va danh ((ca chua) or (dieu cua)) tre*.