Auction models for tickets
First, you should note that there is a Revenue Equivalence Theorem that says under a set of conditions, the seller's revenue from using different forms of auctions will be the same. This same result holds also in the multi-object case. 

Thus, if you have $n$ identical objects, you can sell them using a ($n+1$)th price sealed bid auction, where 


each bidder submits a bid,
the highest $n$ bidders each gets $1$ object, and 
they all pay a price equal to the ($n+1$)th highest bid. 


In such an auction, it is a weakly dominant strategy for every bidder to bid their true valuation of the object. The reasoning is similar to the second price auction.