It is mandatory for at least one author of an accepted paper to register and pay the conference fee in order for the paper to include the Conference Program.
If co-author also like to register himself then each co-author has to pay the 75 euro in order to get all things as covered in the fee. Students (include PhD students) may receive 50% support.
There is a possibility to decrease the conference fee up to 50%. Please send a mail to Ivan Ivanov firstname.lastname@example.org