Perhaps you should try some spelling variations:
nghien huu » nghien cuu, nguyen huu, nhiem huu
chong dich » luong dich, hang dich
chong doc » chon loc, hong duc, cuong do
toc sach » hoc sach, doc sach, thuoc sach
sach hoc » cach hoc, sach hoi, mach hoc
tung hoc » trung hoc, tuong hoc, dung hoc
hoc phan » hoc dan, hoc pho
phat van » pham van, phan van, phap van

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 hoc tap, nghien huu tung hoc phan ((chong doc) OR (chong dich)) xa hoi va phat van~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach hoc tap, nghien huu tung hoc phan ((chong doc) OR (chong dich)) xa hoi va phat van".
• Adding a wildcard symbol may retrieve word variants: toc sach hoc tap, nghien huu tung hoc phan ((chong doc) OR (chong dich)) xa hoi va phat van*.