Separate them with comma.

Example:http://www.youtube.com/user/designcompasscorp,,,,"maxResults=50,orderby=published"

maxResults

The maxResults parameter specifies the maximum number of results that should be included in the result set. This parameter works in conjunction with the start-index parameter to determine which results to return. For example, to request the second set of 10 results – i.e. results 11-20 – set the max-results parameter to 10 and the start-index parameter to 11. The default value of this parameter is 5, and the maximum value is 50. However, for displaying lists of videos, we recommend that you set the maxResults parameter to 10.

 

start-index

The start-index parameter specifies the index of the first matching result that should be included in the result set. This parameter uses a one-based index, meaning the first result is 1, the second result is 2 and so forth. This parameter works in conjunction with the max-results parameter to determine which results to return. For example, to request the second set of 10 results – i.e. results 11-20 – set the start-index parameter to 11 and the max-results parameter to 10.

order

The order parameter specifies the method that will be used to order resources in the API response. The default value is relevance.

Acceptable values are:

 


Note: A user's playlists feed is ordered by publication time beginning with the newest playlist. For a user's subscriptions feed, the default ordering is arbitrary.

Even more about query parameters here