Charles Spurgeon
When preaching and private talk are not available, you need to have a tract ready. Get good striking tracts or none at all. But a touching gospel tract may be the seed of eternal life. Therefore do not go out without your tracts.

All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work.
2 Timothy 3:16-17