Sources of market power -Entry to the market is blocked.
-Entry could be patent or trademark protected
-Entry could be government protected
-Entry could be protected by economies of scale 

Profit maximization 

Monopoly-Profit Maximizing

Loss Minimizing

Monopoly-Loss Minimizing

Technical Aspects of Monopoly 
    Inefficiency of monopoly
        Consumer and Producer Surplus
        Dead weight loss

Monopoly Analysis

ACDC Monopoly Dead Weight Loss

ACDC-Monopoly-Elastic vs. Inelastic

Price discrimination

ACDC-Monopoly-Price Discrimination

Natural monopoly

ACDC-Monopoly-Regulating Natural Monopoly

Additional Sources:

ACDC-Monopoly Review

Khan Academy