. . . "P. K. Nijhawan"@en . "Purushottam Nijhaawan" . "Nijhawan, P. K. (Purushottam Kumar)" . "Nijhaawan" . "Kumar" . . "P."@en . "K."@en . . . "Purushottam" . "Nijhawan"@en . "Purushottam Kumar Nijhawan" .