Pac Spero

TRIAL GUIDELINES FOR THE CONSERVATION OF VIRGINIA'S HISTORIC BRIDGES. FINAL REPORT

H J Kittell, Pac Spero, E DeLony, 1986 .

A survey and photographic inventory of concrete and masonry arch bridges in Virginia.

Pac Spero, 1984 .

THE PHOTOGRAMMETRIC RECORDING OF HISTORIC TRANSPORTATION SITES

Pac Spero, 1983 .