Comparisons

Works of fiction resemble each other either because one influenced the other or because they address common themes. In HG Wells' works: 

the Time Traveller finds Morlocks and Eloi in 802,701 AD;
Cavor and Bedford find Selenites in the Moon;
Martians invade Earth. 

Thus, time travel, travel to the Moon and alien invasion of Earth occur in separate works. 

In Edgar Rice Burroughs' (ERB's) works:

John Carter finds green and red Martians on Mars;
Carter's successors find Kalkars in the Moon;
Kalkars invade Earth.

Thus, astral travel to Mars, travel to the Moon and alien invasion of Earth occur in successive works. In fact, ERB connected all his series and incorporated time travel:

in The Eternal Savage, someone travelling to Africa to visit Tarzan accidentally travels into the far past instead;
Tarzan visits the Earth's Core;
Gridley's radio contacts the Earth's Core and Carter's Mars;
the first Venus book refers to the events of Tarzan at the Earth's Core;
the Moon Trilogy is a sequel to the Martian series;
astral travel takes a later character to an extra-solar planet.

In ERB's inhabited Solar System, human beings are found inside the Moon and on Venus, Mars, a Martian moon and Jupiter and are said to exist on Mercury. They even exist also on the extra-solar planet.

Wells started to connect his works, then abandoned the idea. Martians:

observe Earth in "The Crystal Egg";
invade Earth in The War of the Worlds;
were mentioned in an early edition of The Sleeper Wakes
which is set in the same future society as "A Dream of Armageddon" and "A Story of the Days to Come",
the latter a sequel to "A Story of the Stone Age". 

That is it for Wellsian interconnections. When the reference to Martians was removed from The Sleeper Wakes, the main link was severed. Wells had started to move towards an inhabited Solar System. There were Selenites and Martians and the latter also invaded Venus.

ERB had dinosaurs on an island called the Land that Time Forgot during a War.
DC Comics had the War that Time Forgot on Dinosaur Island. 

In the DC Multiverse, different times and places intersected during the climactic Crisis on Infinite Earths.
In Michael Moorcock's Multiverse, different times and places intersect during the periodic Conjunction of the Million Spheres.

Moorcock's Multiverse contains an ERBian pastiche which uses the idea of travel to the far past to explain how a twentieth century character can visit a humanly inhabited Mars. Thus, Moorcock creatively combines ideas that ERB had treated separately. Two other writers of Martian adventures should be mentioned: Edwin Arnold as a possible source for ERB and Otis Adelbert Kline as the imitator and competitor who obliged ERB to retaliate by starting a Venus series.

In the Dan Dare comic strip:

Dare found Treens and Therons on Venus;
Treens invaded Earth which they ruled through robots
until Cadet Spry seized the mike and, imitating the Mekon, ordered the robots to attack the Treens,
thus forcing the Treens to destroy the robots. 

In the Dr Who TV series:

the Doctor found Daleks and Thals on Skaro;
Daleks invaded Earth which they ruled through robotised men
until the Doctor's granddaughter seized the mike and, imitating a Dalek, ordered the robomen to attack the Daleks,
thus forcing the Daleks to destroy the robomen.

The Daleks-Thals and Daleks Invasion Earth stories were adapted as feature films starring Peter Cushing not as a Time Lord called the Doctor but as an English inventor called Doctor Who, thus closer to the Wellsian original. The originals of the Doctor and his assistants contending with Daleks, robomen, cybermen etc are the Time Traveller and Weena contending with Morlocks, then the Time Traveller alone contending with giant crabs and the end of life on Earth.

Daleks, like Wellsian Martians, are evolved beings inside protective machines. John Christopher acknowledged that he had unconsciously plagiarised Wells when he wrote about extra-solar invaders in tripods.

Wells, ERB, Moorcock, DC Comics, Dan Dare and Dr Who: this summarises a lifetime of appreciating imaginative fiction. In the above summaries, Earth is invaded from Mars, the Moon, Venus and two extra-solar planets. Some similarities are acknowledged influences. Others are sources of wonder.