Please provide the references for the g.problem

[zixiangliwust]

Where are the G1, G2, G3, G4 and so on for the single objective taken from? Please provide the reference.

[blankjul]

I had to look up the source. It is now added as a comment to the source file (in the release branch).

Liang, Jing J., Thomas Philip Runarsson, Efrén Mezura-Montes, Maurice Clerc, Ponnuthurai Nagaratnam Suganthan, Carlos A. Coello Coello, and Kalyanmoy Deb.
Problem Definitions and Evaluation Criteria for the CEC 2006 Special Session on Constrained Real-Parameter Optimization.