. "Four-potential" . . "4-potential" . "electromagnetic scalar potential" . "four-vector potential" . "electromagnetic field" . "electrodynamic potential" . . . . . "Electromagnetic 4-potential" . "Electromagnetic four-potential" . "electromagnetic vector potential" . "EM 4-potential" . "electromagnetic potential" . "electromagnetic 4-potential" . "Electromagnetic four-potential" . "electromagnetic four-potential" . "four-potential" .