routing - Can I send a WAN and LAN connection over the same cable? - Super User
networking - Expanding wireless coverage: What are the differences between LAN to LAN and LAN to WAN when it comes to connecting two wireless routers? - Super User
How to set up router connection for Lan-Lan or Lan-Wan
Amazon.com: WAVLINK WiFi Router AC1200, Dual Band 5GHz+2.4GHz Wireless Router with Gigabit WAN/LAN, Long Range Coverage for Home and Office, Supports Router/Access Point/Repeater Mode : Electronics
Home networking explained, part 9: Access your home computer remotely - CNET