Step 1: Identify the external source of recruitment in the case.
Veer Infrastructure placed a physical notice at the entrance of the construction site inviting daily wage laborers to report on a specified date. This is the hallmark of a specific external recruitment method.
Step 2: Name the source.
The external source being used here is Direct Recruitment (also called Gate Hiring or Factory Gate Recruitment).
Step 3: Explain Direct Recruitment.
In direct recruitment, the company places a notice on its notice board or at its gate, clearly specifying the details of available vacancies - the type of work, duration, wages, and any eligibility requirements. Job seekers from outside the organization see the notice and gather at the premises on the specified date and time.
Step 4: Explain how selection happens.
The selection under direct recruitment is done on the spot. Representatives or supervisors assess the assembled candidates informally and hire those who fit the job requirements immediately, without elaborate interviews or written tests.
Step 5: Connect to the case.
In the case, the site supervisor placed a notice at the entrance specifying the need for daily wage laborers with experience in masonry or carrying materials, asking them to report on a Monday morning. This is a textbook example of direct recruitment.
Step 6: Conclude.
The external source of recruitment in the case is Direct Recruitment, where a notice posted at the workplace gate invites casual laborers to report for immediate, on-the-spot selection.
\[ \boxed{ \text{External source: Direct Recruitment (gate hiring via notice at the construction site)} } \]