“…The extended forms and models can deal with different types of portfolio selection issues according to the different aims. Second, to optimize the existing portfolio selection methods, some improved models have been presented, such as the mean absolute deviation portfolio model (Simaan, 1997), the Bayesian framework portfolio model (P astor, 2000), the mean-VaR portfolio model (Alexander & Baptista, 2002), the chance constrained portfolio model (Abdelaziz et al, 2007), the constrained fuzzy analytic hierarchy portfolio model (Nguyen & Gordon-Brown, 2012), the risk-return portfolio model (Brandtner et al, 2018), and the mean-risk portfolio model (Mehralizade et al, 2020). Third, to deal with different real problems, some new models have been designed.…”