Perhaps you should try some spelling variations:
phan nghien » phap nghien, luan nghien
nha nghien » phap nghien, cham nghien, chua nghien
thi nghiem » thuc nghiem
nghiem bai » nghiem ban, nghiep bai, nghiep tai
khach thi » khac thi, khach trai, quach thi
toc sach » hoc sach, doc sach, thuoc sach
te khach » he khach, tri khach, tan khach
bai hoc » dai hoc
de hoc » te hoc, du hoc, dien hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( toc sach ((nha nghien) OR (phan nghien)) de hoc ) or ( te khach thi nghiem bai hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( toc sach ((nha nghien) OR (phan nghien)) de hoc ) OR ( te khach thi nghiem bai hoc ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( toc sach ((nha nghien) OR (phan nghien)) de hoc ) or ( te khach thi nghiem bai hoc ))*".