拙著 is a self-deprecating courtesy term — only use about your OWN writing, never someone else's. Part of the
拙- (zhuō-) family of humble self-references:
拙作 (zhuōzuò, my humble work),
拙见 (zhuōjiàn, my humble opinion),
拙荆 (zhuōjīng, my wife — very old-school). For a respectful reference to someone else's book, use
大作 (dàzuò) or
尊著 (zūnzhù).
