Delhi Police Head Constable Exam Guide Hindi Book is published by Ramesh Publishing House. It is available in Hindi medium. Best Reference book cum Exam Preparation book for Delhi Police Head Constable (HC) Assistant Wireless Operator, Tele-Printer Operator Recruitment Exam. Designed and developed as per the exam syllabus & question paper pattern. Delhi Police: Head Constable (Asstt Wireless Operator/ Teleprinter) Exam Guide.