Ubuntu – Error while cron scheduling a sh script

This is my shell script which i want to schedule using cron job.

parser.sh

#!/bin/bash

source .profile
workon venv
cd /home/ashish/deployments/myproject

export DJANGO_SETTINGS_MODULE=myproject.settings_production
python /home/ashish/deployments/myproject/myproject/manage.py parse_data

Cron job-

*/15 * * * * . /home/ashish/parser.sh

Whenever this cron job runs i receive a mail with errors:

/bin/sh: 6: /home/ashish/parser.sh: source: not found
/bin/sh: 7: /home/ashish/parser.sh: workon: not found
Traceback (most recent call last):
  File "/home/ashish/deployments/myproject/myproject/manage.py", line 8, in <module>
    from django.core.management import execute_from_command_line
ImportError: No module named django.core.management

When i run this script from terminal –

. parser.sh    #this gives no error

sh parser.sh   #this gives errors
/bin/sh: 6: /home/ashish/parser.sh: source: not found
/bin/sh: 7: /home/ashish/parser.sh: workon: not found

What can be the possible error in this script ?