Is it true that there are 5 principal types of meditations?

According to some there are 5 principal types of meditations: 1. Metta-Bhavana 2. Karuna-Bhavana 3. Mudita Bhavana 4. Asubha Bhavana 5. Upekka Bhavana I couldn't find any link which could support the above mentioned meditation theory. So my questions are: Is it true that there are 5 principal types of Meditations? Can anyone provide me the original links where Buddha lays down the above mentioned 5 types of meditation?