Perhaps you should try some spelling variations:
nghien huu » nghien cuu, nguyen huu, nhiem huu
phan hong » phan cong, pham hong, phan song
sach hoc » cach hoc, sach hoi, sach duoc
mach hoc » cach hoc, dich hoc, anh hoc
tung hoc » trung hoc, tuong hoc, dung hoc
hoc phan » hoc dan, hoc pho
hong doc » chong doc, hong duc, huong doi
phat van » pham van, phan van, phap van
doc xa » duoc xa, hoc xa, do xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((sach hoc) OR (mach hoc)) tap, nghien huu tung hoc phan hong doc xa hoi va phat van~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sach hoc) OR (mach hoc)) tap, nghien huu tung hoc phan hong doc xa hoi va phat van".
• Adding a wildcard symbol may retrieve word variants: thuat ((sach hoc) OR (mach hoc)) tap, nghien huu tung hoc phan hong doc xa hoi va phat van*.