Penetration of the political institutions of Guatemala by the international Communist movement: threat to the peace and security of America and to the sovereignty and political independence of Guatemala.

Mode of access: Internet.

Long Term Pavement Performance computed parameter : frost penetration /

"HRDI-13/11-08(1M)E"--P. 4 of cover.

Monte Carlo calculations of gamma ray penetration /

"Task No. 70717"

Some methods for improving water penetration in irrigated lands.

Mode of access: Internet.