@article{MZM_2012_91_6_a7,
     author = {Q. X. Pan and X. L. Zhu},
     title = {$\mathcal{GP}${-Projective} and $\mathcal{GI}${-Injective} {Modules}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {870--879},
     publisher = {mathdoc},
     volume = {91},
     number = {6},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2012_91_6_a7/}
}