Bound with this are: Implicit map projections in computer print-outs / by William Warntz ; Proposed solution for the minimum path problem / by C. Ernesto S. Lindgren ; The identification of mixed hexagonal central place hierarchies, with examples from Finland, Germany, Ghana and Nigeria / by Michael J. Woldenberg ; Determination of geodesic and minimum path lines by graphical methods / by C. Ernesto S. Lindgren ; The geometry of mixed hexagonal hierarchies in the context of central place theory / by C. Ernesto S. Lindgren.