Perhaps you should try some spelling variations:
phan chong » phan cong, phan hong, phap chong
chong hoc » chung hoc, chong doc, thong hoc
khoa hoc » hoa hoc
hoc phan » hoc dan, hoc pho
dap nhan » dap nha, dac nhan, dam nhan
nhan dan » phan dau, gian dan, nhan tai
tu sach » thu sach, su sach, tu cach
te sach » toc sach
hoc xa » hoc ma

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 (te sach)) hoc tap, nghien cuu khoa hoc phan chong hoc xa hoi dap nhan dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) hoc tap, nghien cuu khoa hoc phan chong hoc xa hoi dap nhan dan".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) hoc tap, nghien cuu khoa hoc phan chong hoc xa hoi dap nhan dan*.