Please use the following to cite the JMLR-MLOSS paper introducing MEKA:

@article{MEKA,
    author = {Read, Jesse and Reutemann, Peter and Pfahringer, Bernhard and Holmes, Geoff},
    title = {{MEKA}: A Multi-label/Multi-target Extension to {Weka}},
    journal = {Journal of Machine Learning Research},
    year = {2016},
    volume = {17},
    number = {21},
    pages = {1--5},
    url = {http://jmlr.org/papers/v17/12-164.html},
}