[Committee hearings] serial, 90th Congress. 1. Coast Guard authorization, 1968, icebreaker program, hearings before Subcommittee on Coast Guard, Coast and Geodetic Survey, and Navigation and [full committee] 90th Congress, 1st session, on H.R. 5401, H.R. 5424, H.R. 5451 [and] icebreaker program, Feb. 21 [and] 23, 1967.