@article{10_1017_S0017089511000498,
     author = {WENPENG, ZHANG},
     title = {A {MEAN} {VALUE} {RELATED} {TO} {D.} {H.} {LEHMER'S} {PROBLEM} {AND} {THE} {RAMANUJAN'S} {SUM*}},
     journal = {Glasgow mathematical journal},
     pages = {155--162},
     year = {2012},
     volume = {54},
     number = {1},
     doi = {10.1017/S0017089511000498},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089511000498/}
}