1st Class or 2nd Class Control

angle Class Ⅱand skeletal class I malocclusion

Class Ⅰ and Class Ⅱ highways

Class A and class B infectious diseases

Class I and Class II

(Weakly) covering congruence

∨-congruence

0-bisimple congruence

congruence

congruence circuit

congruence kernel

congruence model

congruence of L-semilattice

congruence of pulse with four seasons

congruence relations

congruence system of first degree

congruence theorem

Congruence velocity

linear congruence generator

method of goal congruence