Perhaps you should try some spelling variations:
dung khoa » dung cho
sach hoc » cach hoc, sach hoi, mach hoc
cuu dong » cuu cong, cuu tong, cuu long
dong hoc » dong co, dong luc
hoc dung » hoc ung, tac dung, hoc cong
khoa hoc » hoa hoc
vu sach » vu bach, su sach, vu khach
hoi dan » hoa dan, hoi dap, thoi dai
phan va » phan van, nhan va, han va
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 dong hoc dung khoa hoc xa ((hoi dan) OR (hoc dan)) phan va~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach hoc tap, nghien cuu dong hoc dung khoa hoc xa ((hoi dan) OR (hoc dan)) phan va".
• Adding a wildcard symbol may retrieve word variants: vu sach hoc tap, nghien cuu dong hoc dung khoa hoc xa ((hoi dan) OR (hoc dan)) phan va*.