A man wonders if his wife’s child is really his; but how could anyone know?
The protagonist is curing lepers.
There are no spaces between the words.
The character drives a Meteor Custom DeLuxe. Or a 56 Buick Roadmaster.
(Nero Wolfe)
Its written on a wall in some variant of pictoglyphs.
-or on clay tablets.
In-vitro fertilization and surrogate motherhood is a far-out science fiction concept for the future.
The book makes a point of telling the reader that it’s set in the future, by featuring hand-held (or wrist-worn) computers.
After dinner, the gentlemen retreat to the smoking room to discuss serious matters.
The main character charges $25 a day plus expenses, which some clients find a bit pricey.
When a radio transmitter is described as sending Hertzian waves out into the aether.
When dinosaurs have bent legs like tortoises and iguanas, sauropods are swamp dwellers and theropods walk upright.
When space travel is described as venturing into the ionosphere.
When your history book refers to Native Americans as red men and that women may someday (shudder) vote.
When a farm boy plowing the back forty with a mule aspires to become a starship pilot. For which it helps that he’s memorized the entire book of logarithms.
When there’s an inscription on the inside cover that reads
To Dad, from Katie and Ed
Dec. 25 , 1946
(my used bookstore copy of George R. Stewart’s “Names on the Land: A Historical Account of Place-Naming in the United States”)
It takes place in the future and the computers still have vacuum tubes.
And CRT monitors
Its Dewey Decimal number is 1.
Nonsense; if the Giant Brain cannot speak answers are fed out on a paper tape.

The cover is falling apart
No, that’s just a who the fuck cares if it’s a good product modern book. I’ve had covers fall apart on five year old books. Really old books have sewn-in pages and cloth-covered covers, and their pages are still white and pliable. I have a few of those, mostly inherited from my grandmother.

The main character calls the operator to get the number for the police.
And the number is in exchange name format like LAkewood-2697