Perhaps you should try some spelling variations:
sach nganh » sach ngan, sach tranh, cac nganh
xac nganh » cac nganh, hoc nganh, da nganh
khoa kham » khoa than
nganh co » nganh cong, nganh hoa, nganh y
kho khan » khoa than
vu sach » vu bach, su sach, vu khach
thu xac » thau xay

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu sach nganh co khi đong luc ) OR ( thu xac nganh ((khoa kham) OR (kho khan)) đong luc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( vu sach nganh co khi đong luc ) or ( thu xac nganh ((khoa kham) OR (kho khan)) đong luc ))~".
• Adding a wildcard symbol may retrieve word variants: (( vu sach nganh co khi đong luc ) or ( thu xac nganh ((khoa kham) OR (kho khan)) đong luc ))*.