The C-visa or Schengen visa is the visa which is to be applied by the doctors who wanted to visit Netherlands in order to attend any conference there. The visa is valid from 90 days to 3 months.

The following are the general requirements to apply for the visa:

• You must have either passport or identity document.
• You must be able to give the specific reason for your visit.
• You should have sufficient means for your trip.
• You must also have adequate travel medical insurance.
• There must also be a ‘no risk settlement’, which gives the authorities an assurance that you don’t have any intention to in Netherlands permanently.

The following are the list of documents you need to produce while applying for the visa:

• A valid ID document, for example a passport, which should be no more than 10 years old and valid for three months longer than the date specified as the end of the visa period;
• Information about the reason for your trip, for example, a hotel reservation, invitation from a company to attend a conference, or a ‘proof of sponsorship' form completed by a person sponsoring (vouching) for you;
• A valid ID document, for example a passport, which should be no more than 10 years old and valid for three months longer than the date specified as the end of the visa period;
• Information about the reason for your trip, for example, a hotel reservation, invitation from a company to attend a conference, or a ‘proof of sponsorship' form completed by a person sponsoring (vouching) for you;

http://www.expatica.com/nl/visas-and-permits/Short-stay-visa-for-visiting-the-Netherlands_108432.html