. . "The period of time or point in time to which the measured observation is intended to refer."@en . . "referen\u010Dn\u00ED obdob\u00ED"@cs . . "\u010Casov\u00E9 obdob\u00ED nebo m\u00EDsto v \u010Dase, pro kter\u00E9 plat\u00ED m\u011B\u0159en\u00E1 hodnota."@cs . "reference period"@en . .