Seuss wrote just 44 books with equivalent rate of sales and like Stine and Patten are typically the top ten. There are many such themes woven throughout the series, yet they are not heavy-handed.
'Elfhunter' can be enjoyed on particularly superficial level alone, if desired. http://Choongsoo.kr/bbs/board.php?bo_table=free&wr_id=241910