Question:  What are two other big American Movie theater chains besides the one that is present at the Yorktown Center in Lombard?

Context paragraphs:
National Association of Theatre Owners: The National Association of Theatre Owners (NATO) is a trade organization based in the United States whose members are the owners of movie theaters. Most major theater chains are members, as are many independent theater operators; collectively, they account for the operation of over 32,000 motion picture screens in all 50 U.S. states and 81 other countries.

AMC Theatres: AMC Theatres (originally an abbreviation for American Multi-Cinema, often referred to simply as AMC and known in some countries as AMC Cinemas) is an American movie theater chain owned and operated by AMC Entertainment Inc., which is itself owned by AMC Entertainment Holdings, Inc., majority-owned by Chinese conglomerate Dalian Wanda Group.  Founded in 1920, AMC has the largest share of the American theater market ahead of Regal Entertainment Group and Cinemark Theatres.  The chain has 86 locations in mainland China, home of the Dalian Wanda Group.  The company's headquarters are located in Leawood, Kansas.

Somerville Theatre: The Somerville Theatre is an independent movie theater and concert venue in the Davis Square neighborhood of Somerville, Massachusetts, United States.  Over one hundred years old, the Somerville Theatre started off as a vaudeville house and movie theater.  The theater has since transitioned and now operates as a live music venue and first-run movie theater.  As a music venue, the theater has played host to many historic concerts, including the first of the two Last Dispatch concerts, two shows by Bruce Springsteen in 2003, and a performance by U2 in 2009.  Recent live performances have included Ryan Adams & the Cardinals, Cursive, Norah Jones, The Jonas Brothers, Joan Baez, and the John Butler Trio.  The building also hosts the Somerville branch of the Museum of Bad Art.

Pantages Theatre (Salt Lake City): The Pantages Theatre is an historic theater in Salt Lake City, Utah in the United States of America.  It opened in 1918 as the Pantages Theater, after the name of its owner, Alexander Pantages.  Babe Ruth performed there in 1927.  Abbott and Costello, Will Rogers, and many other celebrities also performed in the theater during its heyday.  Formerly also known as the RKO Orpheum and later as the Utah Theater, it was built in 1918.  The theater was originally built for vaudeville at the princely sum of over two million dollars, making it among the most expensive and opulent structures in the Pantages theater chain.  The structure, designed by celebrated architect B. Marcus Priteca, was built in the interior of a city block, and reached by long grand gallery extending to Main Street.  The interior lobby was done in an exotic neo-classical style, [the touted Pantages Greek] with ornate plaster work, an inlaid marble floor, and ramps ascending to the mezzanine level.  The interior was accented with Alaskan marble and faux tile.  The auditorium's proscenium was flanked with marble columns and gilded opera boxes.  The hall's ceiling was decorated with a Tiffany skylight.  The main floor of the auditorium seated 1700, and the balcony accommodated an additional 600 patrons.  The theater functioned as a vaudeville venue through the 1920s, before being converted into a movie palace during the 1930s.  Through most of the decade, the theater was owned by Radio-Keith Orpheum and was renamed the RKO Orpheum.  By 1937, however, it had taken the name the Utah Theater, which has endured to the present.  One of the highlights of the Utah as a movie venue was during the mid-1960s, when the Sound of Music had a run in the theater that lasted two years.  In 1968, the theater was split into upper and lower levels, with the balcony being transformed into a second auditorium.  This architectural arrangement, commonly known as "piggybacking," was frequently imposed on older traditional theaters during the 1960s and early 1970s.  With this transformation, an escalator ascended from the Utah's mezzanine to the top rows of the balcony.  During the remodeling the proscenium, box seating and some of the elaborate ornamentation was removed.  In 1988, the structure ceased operation as a movie theater, and was used by local dance company until 1992, when the building was sold.  After passing through the hands of various owners, the vacant building was purchased by the Salt Lake City Redevelopment Agency in 2009.  At this time there are no definitive plans for the future of this theater.

Yorktown Center: Yorktown Center is an enclosed regional shopping mall located in the village of Lombard, a suburb of Chicago, Illinois, United States.  Anchor stores include Carson's, JCPenney, and a flagship Von Maur (whose location is the second largest in the chain, the largest being at Perimeter Mall that opened in 2012 in Dunwoody, Georgia).  The mall also features two junior anchor stores, HomeGoods and Marshalls, and more than 100 other stores on its two levels.  Other amenities include a food court, a movie theater (AMC Theatres, formerly a General Cinema), and an outdoor concourse of shops known as The Shops on Butterfield.

Bow Tie Cinemas: Bow Tie Cinemas is an American movie theater chain, with 59 locations in Colorado, Connecticut, Maryland, New Jersey, New York, and Virginia.  As of 2013, it is the eighth-largest movie theater chain in the United States and is the oldest, having been founded in 1900.  Bow Tie Cinemas is family-owned and has been for four generations.

List of movie theaters: This is a list of movie theaters.  See also List of cinema and movie theater chains, which contains a number of theatre "chains" comparable to the number of individual theatres in this list.

Movie theaters in the Netherlands: There are 137 movie theaters and 31 arthouse cinemas in the Netherlands, with a total of ca. 675 screens, in addition to 79 small arthouse cinemas and a number of adult movie theaters.  The main movie theater chains in the Netherlands are Pathé, Jogchem's, Wolff Cinema Groep, and Utopia/Utopolis.

George Lefont: George Lefont is an American movie theater industry businessman from Berkeley, California.  He owns Lefont Sandy Springs, a movie theater in Sandy Springs, Georgia that is the most common venue for the Atlanta Jewish Film Festival.  His previous endeavours include the Silver Screen, a theater in Buckhead he founded in 1976, and the Coach and Six Restaurant in Atlanta, which he owned prior to selling it in 1994.  He also purchased the Plaza Theatre in 1983, after which he converted its balcony into a second theatre with 200 seats.  His repertoire of theaters in Metropolitan Atlanta have included The Screening Room on Piedmont Rd., Ansley Cinema on Monroe Dr., Tara on Cheshire Bridge Road, Toco Hills on Clairmont Rd., Garden Hills Cinema on Peachtree Rd., The Marietta Star probably on Roswell Rd at I-75 in the Town & Country Shopping Center, and a fourplex in Athens.

Carver Theatre (Columbia, South Carolina): Carver Theatre is a historic African American movie theater in Columbia, South Carolina.  It was built in 1941, and is a two-story, rectangular, brick commercial building.  It has a flat roof and a vertical marquee.  It operated as a movie theater until 1971.

Supporting paragraphs: Yorktown Center AMC Theatres
Answer: Regal Entertainment Group and Cinemark Theatres