perfect plasticityperfect solutionperfect stoneperfectly mobile componentperfectly plastic materialsperforateperforated cover plateperforated crustperforated metal basketperforated plateperforationperforation depositperformance of the damperformance testspergelationpergelic temperature regimepergelisolperhamitepericarppericlasepericlinepericline twin law or twin law or twin lawpericoelpericolpatepericystperidotperidotite or peridotites or peridotitesperidotite shellperiembryonic chamber or periembryonic or periembryonicperigean tideperigeeperignathic girdle or girdle or girdleperihelionperilumenperimeter groutingperimeter of watershedperineumperiod or periods or periodsperiodic springperiostracumperipheral counterperipheral fault or fault or faultperipheral moraineperipheral rimperipheral sinkperipheral streamperipolar space or peripolar or peripolarperiproct or periproctal or periproctalperisome or perisoma or perisomaperistomice
