एपीए उद्धरण

Unnikrishnan Puthoor. (1969). Chatuppu Nilam. Sahitya Pravarthaka Co-operative Society Ltd.

शिकागो स्टाइल उद्धरण

Unnikrishnan Puthoor. Chatuppu Nilam. Koottayam: Sahitya Pravarthaka Co-operative Society Ltd, 1969.

एमएलए उद्धरण

Unnikrishnan Puthoor. Chatuppu Nilam. Sahitya Pravarthaka Co-operative Society Ltd, 1969.