| Mech, Fritts, Radde, Paul | L.D., S.H., G.L., W.J. | Wolf distribution and road density in Minnesota. | 1988 | Wildlife Society Bulletin 16:85-87 |
From USDI 1988:
"Data is consistent with Thiel (1985). Wolves generally do not occur where road densities exceed 0.58 km/sq km."