Dragonslayer is a novel by Wayland Drew published in 1981.
Dragonslayer is a novelization of the film Dragonslayer.
[1] David St. Marie reviewed Dragonslayer in Ares Magazine #9 and commented that "I found Dragonslayer to be a solid novel, overall.
It has failings, but most of those symptomatic of novels based on scripts have been avoided.
"[1]