Confrontations: A Scientist's Search for Alien Contact

Confrontations (Ballantine, 1990), the second book of Jacques Vallée's trilogy, is his field casebook: he travels to investigate encounters himself rather than rely on reports, and concentrates on cases with physical effects, including injuries. Its best-known chapters describe his visits to northern Brazil, where people around Colares and the island of Marajó said lights from the sky had burned and attacked them in 1977, the wave investigated by the Brazilian Air Force's Operação Prato. Vallée treats the injuries as real and the phenomenon as potentially dangerous, without claiming to know its source.

Sources: Wikipedia · Operação Prato file