can any one explain me about the concept of SPGL1 and BPDN?

Hi,(<mailto:[e-mail] [e-mail]>)

can any one please explain me about the concept of basis pursuit(BP) , basis pursuit denoising(BPDN) and spectral projected gradient(SPGL1) for sparse representation ?

my mail id is "[e-mail]". and it is very helpful to send useful study materials to my mail id regarding these concepts.

Thanks in advance