Horst Rittel and Melvin Webber first coined the term "wicked problems" in a 1973 work in the journal, Policy Sciences, "Delimmas in a General Theory of Planning".    By definition, wicked problems aren't totally definable but share 10 characteristics, as revisited by Crowey and Head in  Policy Science (2017) 50:539–547: 

Proposition 1 There is no definitive formulation of a wicked problem.

Proposition 2 Wicked problems have no stopping rule.

Proposition 3 Solutions to wicked problems are not true-or-false, but good-or-bad.

Proposition 4 There is no immediate and no ultimate test of a solution to a wicked problem.

Proposition 5 Every solution to a wicked problem is a ‘one-shot operation’; because there is no opportunity to learn by trial-and-error, every attempt counts significantly.

Proposition 6 Wicked problems do not have an enumerable (or exhaustively desirable) set of potential solutions, nor is there a well-described set of permissible operations that may be incorporated into the plan.

Proposition 7 Every wicked problem is essentially unique.

Proposition 8 Every wicked problem can be considered to be a symptom of another problem.

Proposition 9 The existence of a discrepancy representing a wicked problem can be explained in numerous ways. The choice of explanation determines the nature of the problem’s resolution.

Proposition 10 The planner has no right to be wrong.

 

The three wicked problems being explored are gender inequality, mental health, and waste (sustainable consumption).  

You will want to think of synonyms for these problems for your research.  

For example for the wicked problem of gender inequality.  Other similar terms could be women in IT, employee recruitment, and diversity in the workplace.

The United Nations set broad goals for sustainable development in 2015 and companies have been publishing white papers on these goals.  To look at the goals individually and the subsets of their goals.   Each goal in a sense is a wicked problem to tackle.   To read about the SDG agenda and to see the goals individually, go here.