Perhaps you should try some spelling variations:
nhan khung » nha khung, nhan khong, nha chung
khung hoc » chung hoc, nhung hoc, thuong hoc
sach hoc » cach hoc, sach hoi, mach hoc
cuu cong » cua cong, thu cong, cac cong
cong hoc » dong hoc, cong hoa, cong coc
hoc nhan » hoc nhanh, nhoc nhan, hoc phan
nhan dan » phan dau, nhan tai
gian dan » gian lang
vu sach » vu bach, su sach, vu khach
hoi cau » hoi chu, hoc cau, hoa cau
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: vu sach hoc tap, nghien cuu cong hoc nhan khung hoc xa hoi cau ((nhan dan) or (gian dan))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach hoc tap, nghien cuu cong hoc nhan khung hoc xa hoi cau ((nhan dan) OR (gian dan)).
• Adding a wildcard symbol may retrieve word variants: vu sach hoc tap, nghien cuu cong hoc nhan khung hoc xa hoi cau ((nhan dan) or (gian dan))*.