The short, dark days of winter are the perfect time to curl up under a cozy blanket with a great book. And, as the New Year approaches, it’s the ideal season to reflect on how you performed as a leader the past 12 months and to look for ways to build on your strengths in the days ahead.

Many entrepreneurs aim for what Robert Greenleaf first described in his essay The Servant as a Leader. As he put it, servant leadership “begins with the natural feeling that one wants to serve, to serve first. Then conscious choice brings one to aspire to lead. That person is sharply different from one who is leader first, perhaps because of the need to assuage an unusual power drive or to acquire material possessions.”

The servant-leader model is more relevant than ever today, when lately it seems there is a headline every day about leaders who have misused their power and forgotten about the mission of serving. At the thriving companies you admire, the chances are good that there is a servant leader at the helm.

Here are five books to help you explore the idea of servant leadership, so you can achieve your personal best as a leader in 2018.

Servant Leadership: A Journey into the Nature of Legitimate Power and Greatness 25th Anniversary Edition by Robert Greenleaf

Reading (or re-reading) Greenleaf’s classic book is a great place to start thinking about what servant leadership means today. Greenleaf, who passed away in 1980, was a top executive at AT&T and a visiting lecturer at MIT’s School of Management and Harvard Business School. His ideas on empowering employees caused many leaders to rethink how they ran their companies and offered a new way to grow a company. Whether you run a sole proprietorship where you are managing contractors or have scaled up to hiring employees, Greenleaf offers many relevant ideas on how to build a stronger culture where your team will thrive.

Leaders Eat Last: Why Some Teams Pull Together and Others Don’t by Simon Sinek

Sinek, author of the popular book Start with Why, offers insight on how to build a workplace around trust and avoid the infighting and silos that doom unsuccessful cultures.

In case you’re wondering what the title refers to, Sinek found an answer to a longstanding question in his mind about how great leaders build trust when speaking with a Marine Corps general: “Officers eat last.” Essentially, great leaders put the good of the team ahead of their own, which sets the tone for the entire organization.

If your team is young, make sure you check out the latest edition. Sinek’s 2017 paperback book, originally published in hardcover in 2014, now includes an expanded index on leading millennials.

The Servant Leader: How to Build a Creative Team, Develop Great Morale, and Improve Bottom-Line Performance by James A. Autry

Autry, a former Fortune 500 executive, shows how managing with respect, honesty, love and spirituality will help you become a better leader. This book offers practical advice on how to apply servant leadership in less-than-ideal situations such as conflict and crisis and turn around declining morale. You’ll also learn how to train managers in servant leadership and continue to grow as a servant leader.

The Serving Leader: Five Powerful Actions that Will Transform Your Team, Your Business, and Your Community by Ken Jennings and John Stahl-Wert

This is the season when many people think about giving back, and The Serving Leader offers great ideas on how to do that in the coming year. Originally published in 2003 and updated in paperback in 2016, The Serving Leader is a parable about the lessons a dying father teaches his son that makes it easy to absorb and apply the key principles of servant leadership in every area of your life. If you are looking to bring deeper meaning to your life as a leader, this is a good book to add to your nightstand.

The World’s Most Powerful Leadership Principle: How to Become a Servant Leader by James C. Hunter

Being a servant leader doesn’t mean being wishy-washy. As Hunter explains, servant leaders can be uncompromising in setting the mission and values for a business and how it operates. But unlike old-school, hierarchical leaders who bark orders, servant leaders operate like coaches, empowering employees with the tools they need to thrive and excel. Hunter is a leadership consultant and author whose books are taught in MBA programs around the world.

In today’s highly collaborative, fast-changing work environments, his ideas are more relevant than ever—as are the general ideas behind servant leadership.