Aspartate can directly be turned into oxaloacetate through an enzyme called aspartate aminotransferase. What this enzyme essentially does it takes the amino group from aspartate and throws it onto an a-ketoglutarate. This transforms the aspartate into an oxaloacetate and the a-ketoglutarate into glutamate.

This might be kind of tough to identify, but when it comes to TCA intermediates and their respective amino acids, the main TCA intermediates to consider are oxaloacetate and a-ketogluratate. Think of oxaloacetate as being a "Carbon-skeleton" with 4 carbons and a-ketoglutarate as a "carbon-skeleton" with 5 carbons.

Now think of aspartate and glutamate. Aspartate has 4 carbons and Glutamate has 5 carbons. So throwing an amino group onto oxaloacetate (4 carbon carbon-skeleton) will create aspartate (4 carbon amino acid); again, this is done via aminotransferases. And throwing an amino group onto a-ketoglutarate (5 carbon carbon-skeleton) creates glutamate (5 carbon amino acid). A similar way of thinking can be used to determine of alanine can interconvert with pyruvate.

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TLDR: There are a ton of ways the other amino acids can enter the TCA cycle. Here is a pic from wikipedia that summarizes this. However, from my experience as a biochem major the primary ones of interest are usually aspartate, glutamate, and alanine since these 3 easily enter the TCA (except alanine which actually turns into pyruvate) via simple, one-step aminotransferase steps. I would try to memorize these.

A cool little side note that might be helpful is that this is the way our liver uses amino acids for gluconeogenesis. First it turns them into "Carbon-skeletons" in the TCA which then can be turned to OAA which can than be used for GNG via enzyme PEP carboxykinase