Step 1: Understand the question:
These are three external sources, so each brings candidates from outside the organisation.
We explain campus recruitment, recommendations of employees and the employment exchange.
Step 2: Campus recruitment:
Here the firm goes to colleges and institutes to hire students who are about to finish their courses.
The placement officers of these institutes arrange the interviews for the firm.
It is a good source for fresh and well-trained talent, such as young managers and engineers.
Step 3: Recommendations of employees:
Present employees may suggest the names of their friends and relatives for a vacancy.
Their background is sufficiently known, so the firm can trust such candidates more.
The firm also saves time and cost, since no advertisement is needed.
Step 4: Employment exchange:
Employment exchanges are run by the government and keep a record of unemployed persons who register with them.
Employers inform the exchange about their vacancies and get a list of suitable candidates.
This is a useful source for filling posts of skilled and unskilled workers, and also clerical and operating staff.
Final Answer:
Campus recruitment hires fresh students from institutes, recommendations come from present employees, and employment exchanges supply registered job seekers.