Ask HN: What's a cost effective option for access to academic papers?

I am an undergraduate preparing for graduate studies and am working on a number of extracurricular projects to submit to journals. I have access to Jstor but it is pitifully sparse on the topics I am researching (colonialism, post-colonial societies, conflict & peacekeeping, demographic trends). I'm not looking for a free ride, but I cannot afford the ~$40 per PDF (one of my projects needs access to +30 different papers). Most of what I need seems to be paywalled by individual journals.