PG rated sci-fi books

Displaced Person

Maude

Lepidus the Centurion: A Roman of Today

The Clutching Hand

The Moon Conquerors

A Private Cosmos

More Than Fire

Venus on the Half-Shell

The Other Log of Phileas Fogg

Vital Parts

The Secret of the Round Beast

Here Be Demons

Strange Things Happen in the Woods

The Tery

Tarzan Triumphant

Troika

Experiment in Terra

Mouvar's Magic

On a Planet Alien

Captain Jack Zodiac

Fury

The Hastings Conspiracy

Elleander Morning

Star Trek III: The Vulcan Treasure

The Flesh Mask

Shædow Master

A Madness from Mars

The Lunarian Professor, and His Remarkable Revelations Concerning the Earth, the Moon and Mars, Together with an Account of the Cruise of the Sally Ann

The Tribe

Monastery